Podcasts about calabi yau

Why is star formation the workhorse of the universe? What is a flocculent galaxy? Which cosmic cataclysm creates new globular star clusters? And why are we currently seeing such amazing aurora in unusual places? To find out, Dr. Charles Liu and co-host Allen Liu welcome astronomer Dr. Kelsey Johnson, past president of the American Astronomical Society (AAS) and of the Astronomical Society of the Pacific (ASP), and author of “Into the Unknown – The Quest to Understand the Mysteries of the Cosmos.” As always, though, we start off with the day's joyfully cool cosmic thing, the auroras that have been occurring during the peak of the current solar max period of the roughly 11-year-long solar cycle. From the Mother's Day aurora borealis in May to the amazing night of October 10, when millions of people as far south as Florida and Mexico were treated to one of the most spectacular, vibrant light shows many of them had ever seen. Kelsey shares the story of the first time she saw an aurora, as a high school student in Minnesota who didn't even know what one was. Upon leaving her boyfriend's house at around 2 in the morning, she saw a brilliantly glowing sky. Kelsey's availability bias kicked in, and her assumption was that it had to be either god or aliens, with the latter being the more likely. Needless to say, the next day the front page of the local paper solved the mystery. And then it's on to a nerdy discussion of existential curiosity, deep, philosophical questions, and her book, “Into the Unknown.” You'll hear what drove Kelsey to write the book, and about her lifelong drive to understand our place in the universe. Kelsey and Allen nerd out over Calabi-Yau manifolds (concepts from string theory), imaginary numbers and complex numbers, Euler's Formula and more, and then, thankfully, it's time for our first question. Johnny asks, “What is a flocculent galaxy, and why are they interesting?” Kelsey says that they're spiral galaxies with spiral arms that aren't very pronounced, that are exceptionally “floofy and chaotic” with very different, but very cool star formation. Chuck and Kelsey explain why star formation is the workhorse of the universe and how important it is. Kelsey also explains why globular clusters are her “favorite” type of star cluster. There are about 150 of them living around our galaxy, and they're almost as old as the universe itself, over 10 billion years old. Kesley studies them to learn how the universe was formed and how galaxies came together. New globular clusters are rare, but they can be created by the collision of two galaxies. That's all we could squeeze into Part 1, but come back in two weeks for Part 2 of "Into the Unknown with Dr. Kelsey Johnson." If you'd like to know more about Kelsey, you can visit her website at and follow her on Twitter (X) and Instagram at @ProfKelsey, We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon.   Credits for Images Used in this Episode: Graph of the solar cycle – David Hathaway, NASA, Marshall Space Flight Center, Public Domain May 2024 aurora in Northern Ireland – David Kernan, CC BY May 2024 Aurora from Chihuahua, Mexico – Levi bernardo, CC BY Chuck & Allen's view of the October 2024 aurora – Allen Liu Eugenio Calabi and Shing-Tung Yau – National Science Foundation, Public Domain Eugenio Calabi and Shing-Tung Yau – Konrad Jacobs 3D model of a Möbius Strip – Inductiveload, Public Domain 3D model of a Klein bottle – Lukáš Hozda, Public Domain Number line – Rumil, Public Domain Complex Plane – Brigban, Public Domain NGC 2775, a flocculent galaxy – European Space Agency, CC BY Messier 2, a globular cluster – NASA Hubble, CC BY #TheLIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast  #KelseyJohnson #AAS #ASP #IntotheUnknown #aurora #solarmax #CalabiYaumanifolds #stringtheory #imaginarynumbers #complexnumbers #flocculentgalaxy #spiralgalaxy #globularclusters #starformation #starcluster

Dr. Jordan B. Peterson sits down with physicist and author, Dr. Brian Greene. They discuss the strange conceptualization of “before” the Big Bang, how time might be a microscopic phenomenon, how order existed at the point of the universe's creation, what would happen if you fell into a black hole, and the process of going from understanding to harnessing new insights. Dr. Brian Greene is an American physicist known for his research on string theory. He is a professor of physics and mathematics at Columbia University and the chairman of the World Science Festival, which he co-founded in 2008. Dr. Greene has worked on mirror symmetry, relating two different Calabi–Yau manifolds (concretely relating the conifold to one of its orbifolds). He also described the flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point. This episode was recorded on September 9th, 2024  - Links - For Brian Greene: On X https://x.com/bgreene?lang=en Website https://www.briangreene.org/ "Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe" (Book) https://www.amazon.com/Until-End-Time-Evolving-Universe/dp/1524731676 "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory" (Book) https://www.amazon.com/Elegant-Universe-Superstrings-Dimensions-Ultimate/dp/039333810X 

Today on the Ether we have Mayor Ed Dantes hosting an episode of DeFi 101 with a discussion on NFT Runes, RSTK, Huahua, and a little DeFi 103 on Morph NFT. You'll hear from HolyFolly, Calabi Yau, Tank, Vendetta, bruceman, and more! Recorded on April 29th 2024. Make sure to check out the newest tracks from Finn and the RAC FM gang over at ImaginetheSmell.org! The majority of the music at the end of these spaces can be found streaming over on Spotify, and the rest of the streaming platforms. Thank you to everyone in the community who supports TerraSpaces.

Today on the Ether we have the White Whale community call. You'll hear from Sen Cøm, Sebastian, JGnft, Shark Protocol, HolyFolly, Calabi Yau, Lion DAO, Razzien, Tank, and more! Recorded on April 11th 2024. Make sure to check out the newest tracks from Finn and the RAC FM gang over at ImaginetheSmell.org! The majority of the music at the end of these spaces can be found streaming over on Spotify, and the rest of the streaming platforms. Thank you to everyone in the community who supports TerraSpaces.

Today on the Ether we have Mayor Ed Dantes hosting a discussion on NFTs and DeFi. You'll hear from HolyFolly, NFT Happy Hour, Calabi Yau, Cosmos Joe, NTO, JGnft, and more! Recorded on April 8th 2024. Make sure to check out the newest tracks from Finn and the RAC FM gang over at ImaginetheSmell.org! The majority of the music at the end of these spaces can be found streaming over on Spotify, and the rest of the streaming platforms. Thank you to everyone in the community who supports TerraSpaces.

Today on the Ether we have the White Whale community call. You'll hear from Ponzi_Ninja, Sen Cøm, Sebastian, JGnft, Shark Protocol, HolyFolly, Calabi Yau, CryptoPeener, and more! Recorded on March 21st 2024. Make sure to check out the newest tracks from Finn and the RAC FM gang over at ImaginetheSmell.org! The majority of the music at the end of these spaces can be found streaming over on Spotify, and the rest of the streaming platforms. Thank you to everyone in the community who supports TerraSpaces.

Today on the Ether we have the White Whale community call. You'll hear from Sen Cøm, Sebastian, JGnft, Ginkou, Lord Ginge, Crypto Enthusiast, Vendetta, Mayor Ed Dantes, Calabi Yau, and more! Recorded on March 7th 2024. Make sure to check out the newest tracks from Finn and the RAC FM gang over at ImaginetheSmell.org! The majority of the music at the end of these spaces can be found streaming over on Spotify, and the rest of the streaming platforms. Thank you to everyone in the community who supports TerraSpaces.

Today on the Ether we have the Lion DAO Town Hall. You'll hear from RyanLion, Llewyn, BackBone Labs, Calabi Yau, and more! Recorded on March 5th 2024. Make sure to check out the newest tracks from Finn and the RAC FM gang over at ImaginetheSmell.org! The majority of the music at the end of these spaces can be found streaming over on Spotify, and the rest of the streaming platforms. Thank you to everyone in the community who supports TerraSpaces.

Is it still possible to make a case for string theory? And should we treat the multiverse as a serious idea and explore it mathematically? Here to discuss these fundamental questions with me today is the one and only Brian Greene. Brian Greene, of course, needs no introduction. He is an American theoretical physicist and mathematician. He's a professor at Columbia University and the director of Columbia's Center for Theoretical Physics.  Greene has gained a lot of popularity through his books that bring complex physical issues closer to general audiences: The Elegant Universe (1999), Icarus at the Edge of Time (2008), The Fabric of the Cosmos (2004), and The Hidden Reality (2011), a book he promoted in the TV show The Big Bang Theory!  In this episode, Brian and I discuss the experimental relevance of string theory, the multiverse hypothesis, the likelihood of alien life, and much more.  Tune in! Key Takeaways:  Intro (00:00) What's the experimental minimum? (01:05) String theory's experimental relevance (08:35) An alternative path to Einstein's equations (20:17) Are we neglecting some ideas? (25:35) Calabi-Yau manifolds in string theory (34:26) Lorentz invariance and signals that are faster than the speed of light (40:13) The multiverse and its implications for science (57:47) Inflation doesn't resolve all questions (1:02:18) The role of a scientist as an educator (1:15:04) UFO sightings and the likelihood of alien life (1:27:45) Outro (1:38:26) — Additional resources: 

In this month's podcast, our guest is Yang-Hui He, a Fellow of the London Institute for Mathematical Sciences, which is based at the Royal Institution of Great Britain, professor of mathematics at City University of London, Chang-Jiang Chair professor at Nankai University in Tianjin, as well as Lecturer at Merton College, University of Oxford.In this episode, we've invited him to talk about the interactions between mathematics and physics, how the international education and research experience influence a scientist, and the activities carried out at Chern Institute and Nankai University.Yang-Hui He studied at Princeton University, where he received his Bachelor of Arts in Physics, with a Certificate in Applied Mathematics and a Certificate in Engineering Summa cum Laude (Highest Honours, Phi-Beta-Kappa). He then obtained a Certificate in Advanced Mathematics (Tripos) at Cambridge University, with Distinction. He went on to receive his PhD in theoretical and mathematical physics from MIT and continued at the University of Pennsylvania before joining Oxford University as a FitzJames Fellow in Mathematics and then UK STFC Advanced Fellow in theoretical physics. Prof. He is a mathematical physicist working on various interfaces between geometry and theoretical high energy physics. He is particularly interested in aspects of algebraic geometry in application to, and interacting with, gauge theory as well as string theory, such as Calabi-Yau manifolds, holographic correspondences and string phenomenology. He also has interests in the dialogue between number theory, graph representation theory and gauge theories. Yang-Hui He is author of over 200 scientific publications and also a keen communicator of science. With Springer, he published in 2021 The Calabi-Yau Landscape. From Geometry to Physics, to Machine Learning as volume 2293 of Lecture Notes in Mathematics. In late 2022, the Proceedings of the Nankai Symposium on Mathematical Dialogues will appear, a symposium which celebrated the 110th birthday of S.-S. Chern. 

( To see the video of this show, click here: https://youtu.be/IWy8m6QVxhQ ) Cristina's Instagram, Facebook, YouTube, Twitter and More > https://beacons.page/cristinagomez Patreon Club for Extras & Behind the Scenes: https://www.patreon.com/paradigm_shifts Portals, Wormholes, Stargates, Black Holes; these have become modern day tropes in a variety of TV Shows, Documentaries, and movies. All of them point to hypothetical ways to circumvent linear travel in both Space and Time. The concept of Wormholes was first envisioned and theorized in 1916 by Austrian physicist Ludwig Flamm, while working upon variables in the equations set down by Albert Einstein in 1915 with his ground-breaking Theory of General Relativity. Flamm, while looking for other solutions, arrived at a series of equations that led him to theorize about an object he described as a "white hole," being a zone in space housing a theoretical time reversal of a black hole. According to his theory, entrances to both black and white holes could be connected by a space-time conduit that would in effect 'cheat' normal linear space travel. Then in 1928, Hermann Weyl, a German mathematician, and theoretical physicist, proposed a wormhole hypothesis, but using the term "One-Dimensional Tubes", to speak of a theory of matter in connection with mass analysis of electromagnetic field energy. Later, in 1935, Albert Einstein and Physicist Nathan Rosen announced their wormhole theory which technically became known as an "Einstein-Rosen Bridge", which they had come upon while working on special solutions for 'Einstein Field Equations'. The theory points to a speculative structure that in effect, links two disparate points in spacetime. More precisely it is a transcendental bijection of the spacetime continuum, an asymptotic projection of the Calabi–Yau manifold manifesting itself in Anti-de Sitter space. In this episode, Michael Mataluni will cover aspects of the physics, and science, regarding wormholes and portals, while Cristina will give accounts where mysterious events and disappearances have occurred that would indicate the involvement of portals/wormholes. How close are we to figuring out how to create them..? Are UFOs and Aliens using them to travel to our world..? Do beings from other dimensions use such exotic forms of travel to break the barrier between dimensions to visit our planet, and our Universe..?? These questions and more, will be covered during the show.

Brandish your acutest angles and prepare your panties to vorticitate because this week, for our ninth season premier we go in so hard and so deep that when you suddenly awaken every surface on your body will be bending and sliding through all points and places simultaneously subtended by angles incomprehensible to laypeople!On this extra nerdy episode we discuss:-The Platonic Solids-Is Time the 4th dimension?-Calabi Yau Manifolds-The Mobius Strip-WTF is time?-Why aliens are scary-Are rocks alive?-Explaining the 5th dimension-Edwin A. Abbot's “Flatland”-The Timaeus-The SimsOn this VERY extended episode we also discuss:-The Dimensionality of the 22 Hebrew Letters-Entropy-The Red Shift-The Cosmic Microwave Background Radiation-Dark Energy and Dark Matter-Peter Carroll's “Apophenion”-Non-Big-Bang Cosmology-Explaining the Hypersphere Universe-The Participatory Universe of CHAOS!Sources:A Universe of 10 Dimensions:https://phys.org/news/2014-12-universe-dimensions.htmlPlatonic Solids:https://www.youtube.com/watch?v=dr2sIoD7eeUFlatland: A Romance of many Dimensions:https://www.amazon.com/Flatland-Romance-Dimensions-Thrift-Editions/dp/048627263XApophenion by Peter Carroll:https://www.amazon.com/Apophenion-Chaos-Magick-Paradigm/dp/1869928652iTunes:https://itunes.apple.com/us/podcast/the-whole-rabbit/id1457163771Spotify:https://open.spotify.com/show/0AnJZhmPzaby04afmEWOAVInstagram:https://www.instagram.com/the_whole_rabbit_/Support the show (https://www.patreon.com/thewholerabbit)

Juan & Terence discuss the controversial String Theory and its orgins.

Today we look at the dynamics of string theory and our solar system. We know of 3 Dimensions for sure. Length, Width, and Height, but what if there are infinite dimensions and we can only perceive 3? Quantum Physicists are pushing the agenda for String Theory, M Theory, and Super String Theory. SuperString Theory needs 10 dimensions, M-Theory needs at least 11 dimensions, and Bosonic String Theory would need 26 dimensions. Is the Calabi-Yau manifold an accurate model for 6 collapsable dimensions? A lot of these theories are mathematical and probabilities based with no tangible proof. We will also look at the weirdness that is our Moon and some of it's anomalies. We will look at our sun the power plant of our solar system. We will also analyze the asteroid belt. *If you enjoy our podcast and want to help us grow, check out our Patreon account and enjoy the exclusive material not heard anywhere else. https://www.patreon.com/MikeandMaurice MikeandMauriceMindEscape.com

I’ve got another special treat for you this Tuesday morning? Why? Because I love you, of course! Here’s a two-plus-hour journey into some of the most beautiful music you will hear (until next time, on Headphone Commute), selected by the one and only Roel Funcken, who has graced our ears with his intricate picks, mixdowns, and, most importantly, his very own tracks, appearing on this Calabi-Yau Manifold Mix. The Calabi-Yau manifold is a special type of topological space from mathematics and algebraic geometry, and is used in superstring theory for extra dimensions of spacetime for the six “unseen” dimensions. Just like the music itself, which is compiled from many unreleased pieces (including those of Funcken). For full track listing and more information about this mix, please visit headphonecommute.com

Stanford physics PhD candidate Natalie Paquette studies the interactions between physics and pure mathematics. In this talk, she proposes that string theory can prompt interesting questions in the field of mathematics, and vice versa, using the Calabi-Yau quintic manifold as an example.

In this thesis we study geometric corrections to the low-energy effective actions of string theory. More concretely, we compute higher-derivative corrections to the couplings of three-dimensional, N = 2 supergravity theories and interpret the induced α′-corrections in N = 1, minimal supergravity theories in four dimensions, in the framework of F-theory. These allow for chiral spectra and are therefore phenomenological relevant. We analyzed higher-derivative corrections to M-theory, accessible through its low-energy effective theory, given by eleven-dimensional supergravity. The next to leading order terms to eleven-dimensional supergravity carry eight-derivatives, and are suppressed by lM6 compared to the classical terms, with lM being the eleven-dimensional Planck-Length - the only scale in eleven dimensions. These corrections are lifted from IIA supergravity corrections, which are derived from string scattering amplitudes. The common theme of this thesis is to compactify the bosonic sector of the eleven-dimensional supergravity action, including all known eight-derivative corrections, on a supersymmetric background to find a 3d, N = 2 theory, which then can be lifted to a 4d, N = 1 theory. This goal is approached in several steps. In the classical reduction of eleven-dimensional supergravity the metric background is a direct product of the external space, consisting of two space and one time dimension and the internal eight spacelike-dimensional Calabi-Yau manifold. However, when considering higher-derivative corrections the background has to be altered by introducing a dependence of the external space on the warp- factor, which is a function of the internal space. We find an explicit warped background solution to the eleven-dimensional E.O.M.’s including non-vanishing flux. To check the background for its supersymmetry features one would need to consider the eleven-dimensional gravitino variations at this order in lM . However, these are not known, which leads us to propose higher-order lM -corrected gravitino variations consistent with our background solution. As a next step we dimensionally reduce the bosonic sector of the eleven-dimensional supergravity action including all eight-derivative terms on this warped background and analyze the resulting three- dimensional theory. In this context the interplay of the warp-factor and the higher-derivative terms is of crucial importance. To identify the N = 2 properties of the resulting three-dimensional theory obtained by dimensional reduction, we compare it to the canonical from of three-dimensional N = 2 supergravtiy. We conclude that the reduced action is compatible with N = 2 supersymmetry and give a proposal for the K ̈ahler potential and the complex coordinates, which receive lM6 corrections. Besides a warp-factor contribution, the K ̈ahler potential receives a correction proportional to the third Chern- 2 form of the zeroth order internal background, being the Calabi-Yau fourfold. The complex coordinates are defined as divisor-integrals and are corrected by a warp-factor dependent term as well as one related to the non-harmonic part of the fourth Chern-form, of the zeroth order Calabi-Yau manifold. Thus the couplings of the resulting theory receive besides the warp-factor, in particular geometric corrections of order lM6 . In the first part of this thesis we study a simplified setup, only considering a subset of the relevant eight-derivative corrections in eleven dimensions. Furthermore, we do compactify on the classical background, consisting of the internal Calabi-Yau fourfold without warping and fluxes, to gain a three-dimensional theory. However, we use the M/F-theory duality to uplift the yielded corrections, which results in corrections to the couplings of the four-dimensional theory. In the weak coupling limit we find that these are sourced by the self-intersection curves of D7-branes.

In this thesis we study the geometry and the low-energy effective physics associated with Abelian gauge groups in F-theory compactifications. To construct suitable torus-fibered Calabi-Yau manifolds, we employ the framework of toric geometry. By identifying appropriate building blocks of Calabi-Yau manifolds that can be studied independently, we devise a method to engineer large numbers of manifolds that give rise to a specified gauge group and achieve a partial classification of toric gauge groups. Extending our analysis from gauge groups to matter spectra, we prove that the matter content of the most commonly studied F-theory set-ups is rather constrained. To circumvent such limitations, we introduce an algorithm to analyze torus-fibrations defined as complete intersections and present several novel kinds of F-theory compactifications. Finally, we show how torus-fibrations without section are linked to fibrations with multiple sections through a network of successive geometric transitions. In order to investigate the low-energy effective physics resulting from our compactifications, we apply M- to F-theory duality. After determining the effective action of F-theory with Abelian gauge groups in six dimensions, we compare the loop-corrected Chern-Simons terms to topological quantities of the compactification manifold to read off the massless matter content. Under certain assumptions, we show that all gravitational and mixed anomalies are automatically canceled in F-theory. Furthermore, we compute the low-energy effective action of F-theory compactifications without section and suggest that the absence of a section signals the presence of an additional massive Abelian gauge field. Adjusting our analysis to four dimensions, we show that remnants of this massive gauge field survive as discrete symmetries that impose selection rules on the Yukawa couplings of the effective theory.

In this thesis we study the low-energy effective dynamics emerging from a class of F-theory compactifications in four and six dimensions. We also investigate six-dimensional supersymmetric quantum field theories with self-dual tensors, motivated by the problem of describing the long-wavelength regime of a stack of M5-branes in M-theory. These setups share interesting common features. They both constitute examples of intrinsically non-perturbative physics. On the one hand, in the context of F-theory the non-perturbative character is encoded in the geometric formulation of this class of string vacua, which allows the complexified string coupling to vary in space. On the other hand, the dynamics of a stack of multiple M5-branes flows in the infrared to a novel kind of superconformal field theories in six dimensions - commonly referred to as (2,0) theories - that are expected to possess no perturbative weakly coupled regime and have resisted a complete understanding so far. In particular, no Lagrangian description is known for these models. The strategy we employ to address these two problems is also analogous. A recurring Leitmotif of our work is a transdimensional treatment of the system under examination: in order to extract information about dynamics in $d$ dimensions we consider a (d-1)-dimensional setup. As far as F-theory compactifications are concerned, this is a consequence of the duality between M-theory and F-theory, which constitutes our main tool in the derivation of the effective action of F-theory compactifications. We apply it to six-dimensional F-theory vacua, obtained by taking the internal space to be an elliptically fibered Calabi-Yau threefold, but we also employ it to explore a novel kind of F-theory constructions in four dimensions based on manifolds with Spin(7) holonomy. With reference to six-dimensional (2,0) theories, the transdimensional character of our approach relies in the idea of studying these theories in five dimensions. Indeed, we propose a Lagrangian that is formulated in five dimensions but has the potential to capture the six-dimensional interactions of (2,0) theories. This investigation leads us to explore in closer detail the relation between physics in five and in six dimensions. One of the outcomes of our exploration is a general result for one-loop corrections to Chern-Simons couplings in five dimensions.

Spacemusic 9.8 Gyroscope Show for June 29th 2014 Floating, Grooving, Chillin’ ... from minimal to advanced ambient/electronic music. Spacemusic 9.8 “Gyroscope” has it all in a non-stop 90 minutes (!) mix. Inspired by the advantages of technology for mankind. Pure quality for many different listening occasions. ENJOY! Artists in this mix: Robert Scott Thompson, Rainbow Serpent, Circular, Avilente, SYNC24, Astronaut Ape, Fratoroler, Tripswitch, musicformessier, Synthetic Sunrise. Note: subscribe to Spacemusic Season 9 for automatic downloading. TRACKLIST: [00:00] Spacemusic 9.8 Gyroscope [00:54] R.S. THOMPSON - Zero Point Field buy the album * Arcana * here [04:53] RAINBOW SERPENT - Twelve Celli buy the album * Live at Liphook 2007 * here [16:48] CIRCULAR - Lunokhod buy the album * Moon Pool * here (MUSTHAVE!) [28:00] AVILENTE - Aham buy the album * From Clear Spaces Within * here [31:25] CIRCULAR - Top Dive buy the album * Nordic Circles * here [36:14] SYNC24 - Wake (LIVE edit) buy the album * Comfortable Void * here [42:01] ASTRONAUT APE - Flow buy the album * Ten Minutes Eternity * here [50:13] FRATOROLER - Looking Backward buy the album * Looking Forward * here [1:00:33] CIRCULAR - Theory of Tides buy the album * Moon Pool * here (MUSTHAVE!) [1:10:44] TRIPSWITCH - Calabi Yau buy the track * Calabi Yau * here [01:16:48] MUSICFORMESSIER - Promethia more info about * Musicformessier * here [01:20:42] Beautiful Moments buy the album * Microcosmos Chillout Vol.1 * here [01:28:05] Thank you for your support *** SPACEMUSIC.NL/DONATE *** click here to make a donation END.

Spacemusic 9.8 Gyroscope Show for June 29th 2014 Floating, Grooving, Chillin’ ... from minimal to advanced ambient/electronic music. Spacemusic 9.8 “Gyroscope” has it all in a non-stop 90 minutes (!) mix. Inspired by the advantages of technology for mankind. Pure quality for many different listening occasions. ENJOY! Artists in this mix: Robert Scott Thompson, Rainbow Serpent, Circular, Avilente, SYNC24, Astronaut Ape, Fratoroler, Tripswitch, musicformessier, Synthetic Sunrise. Note: subscribe to Spacemusic Season 9 for automatic downloading. TRACKLIST: [00:00] Spacemusic 9.8 Gyroscope [00:54] R.S. THOMPSON - Zero Point Field buy the album * Arcana * here [04:53] RAINBOW SERPENT - Twelve Celli buy the album * Live at Liphook 2007 * here [16:48] CIRCULAR - Lunokhod buy the album * Moon Pool * here (MUSTHAVE!) [28:00] AVILENTE - Aham buy the album * From Clear Spaces Within * here [31:25] CIRCULAR - Top Dive buy the album * Nordic Circles * here [36:14] SYNC24 - Wake (LIVE edit) buy the album * Comfortable Void * here [42:01] ASTRONAUT APE - Flow buy the album * Ten Minutes Eternity * here [50:13] FRATOROLER - Looking Backward buy the album * Looking Forward * here [1:00:33] CIRCULAR - Theory of Tides buy the album * Moon Pool * here (MUSTHAVE!) [1:10:44] TRIPSWITCH - Calabi Yau buy the track * Calabi Yau * here [01:16:48] MUSICFORMESSIER - Promethia more info about * Musicformessier * here [01:20:42] Beautiful Moments buy the album * Microcosmos Chillout Vol.1 * here [01:28:05] Thank you for your support *** SPACEMUSIC.NL/DONATE *** click here to make a donation END.

We investigate orbifold and smooth Calabi-Yau compactifications of the non-supersymmetric heterotic SO(16)×SO(16) string. We focus on such Calabi-Yau backgrounds in order to recycle commonly employed techniques, like index theorems and cohomology theory, to determine both the fermionic and bosonic 4D spectra. We argue that the N=0 theory never leads to tachyons on smooth Calabi-Yaus in the large volume approximation. As twisted tachyons may arise on certain singular orbifolds, we conjecture that such tachyonic states are lifted in the full blow-up. We perform model searches on selected orbifold geometries. In particular, we construct an explicit example of a Standard Model-like theory with three generations and a single Higgs field.

We evaluate string one-loop contributions to the Kähler metric of closed string moduli in toroidal minimally supersymmetric (Calabi-Yau) orientifolds with D-branes. We focus on the poorly understood N = 1 sectors that receive contributions from all massive string states.

Compactifications of heterotic theories on smooth Calabi-Yau manifolds remain one of the most promising approaches to string phenomenology. In two previous papers, arXiv:1106.4804 and arXiv:1202.1757, large classes of such vacua were constructed, using sums of line bundles over complete intersection Calabi-Yau manifolds in products of projective spaces that admit smooth quotients by finite groups. A total of 1012 different vector bundles were investigated which led to 202 SU(5) Grand Unified Theory (GUT) models. With the addition of Wilson lines, these in turn led, by a conservative counting, to 2122 heterotic standard models. In the present paper, we extend the scope of this programme and perform an exhaustive scan over the same class of models. A total of 1040 vector bundles are analysed leading to 35, 000 SU(5) GUT models. All of these compactifications have the right field content to induce low-energy models with the matter spectrum of the supersymmetric standard model, with no exotics of any kind. The detailed analysis of the resulting vast number of heterotic standard models is a substantial and ongoing task in computational algebraic geometry.

Manschot, J (Universität Bonn) Monday 28 May 2012, 14:45-15:30

Krippendorf, S (Universität Bonn) Thursday 28 June 2012, 17:45-18:00

Gray, J (Ludwig-Maximilians-Universität München) Wednesday 27 June 2012, 14:00-14:35

Lee, S-J (Korea Institute for Advanced Study (KIAS)) Tuesday 26 June 2012, 15:15-15:30

Benini, F (Stony Brook University) Wednesday 28 March 2012, 16:00-17:00

In this thesis we study microscopic aspects of Calabi-Yau black holes in string theory. We compute the absorption cross-section of the space-time massless scalars by the world-volume of D2-branes, wrapped on the S2 of an AdS_2 x S^2 x CY_3 geometry of a four-dimensional D4-D0 Calabi-Yau black hole. The D2-brane can also have a generic D0 probe-brane charge. However, we restrict ourselves to D2-branes with small D0-charge so that the perturbation theory is applicable. According to the proposed AdS_2/QM correspondence the candidate for the dual theory is the quantum mechanics of a set of probe D0-branes in the AdS2 geometry. For small but non-zero probe D0-charge we find the quantum mechanical absorption cross-section seen by an asymptotic anti-de Sitter observer. We repeat the calculations for vanishing probe D0-charge as well and discuss our result by comparing with the classical absorption cross-section. In other project, for a given four-dimensional Calabi-Yau black hole with generic D6-D4-D2-D0 charges we identify a set of supersymmetric branes, which are static or stationary in the global coordinates, of the corresponding eleven-dimensional near horizon geometry. The set of these BPS states, which include the branes partially or fully wrap the horizon, should play a role in understanding the partition function of black holes with D6-charge.

Toda, Y (IPMU, Japan) Thursday 05 May 2011, 15:15-16:15 Spitalfields Day

This thesis is concerned with real mirror symmetry, that is, mirror symmetry for a Calabi-Yau 3-fold background with a D-brane on a special Lagrangian 3-cycle defined by the real locus of an anti-holomorphic involution. More specifically, we will study real mirror symmetry by means of compact 1-parameter Calabi-Yau hypersurfaces in weighted projective space (at tree-level) and non-compact local P2 (at higher genus). For the compact models, we identify mirror pairs of D-brane configurations in weighted projective space, derive the corresponding inhomogeneous Picard-Fuchs equations, and solve for the domainwall tensions as analytic functions over moduli space, thereby collecting evidence for real mirror symmetry at tree-level. A major outcome of this part is the prediction of the number of disk instantons ending on the D-brane for these models. Further, we study real mirror symmetry at higher genus using local P2. For that, we utilize the real topological string, that is, the topological string on a background with O-plane and D-brane on top. In detail, we calculate topological amplitudes using three complementary techniques. In the A-model, we refine localization on the moduli space of maps with respect to the torus action preserved by the anti-holomorphic involution. This leads to a computation of open and unoriented Gromov-Witten invariants that can be applied to any toric Calabi-Yau with involution. We then show that the full topological string amplitudes can be reproduced within the topological vertex formalism. Especially, we obtain the real topological vertex with trivial fixed leg. Finally, we verify that the same results arise in the B-model from the extended holomorphic anomaly equations, together with appropriate boundary conditions, thereby establishing local real mirror symmetry at higher genus. Significant outcomes of this part are the derivation of real Gopakumar-Vafa invariants at high Euler number and degree for local P2 and the discovery of a new kind of gap structure of the closed and unoriented topological amplitudes at the conifold point in moduli space.

Extremal black holes in theories of gravity coupled to abelian gauge fields and neutral scalars, such as those arising in the low-energy description of compactifications of string theory on Calabi-Yau manifolds, exhibit the attractor phenomenon: on the event horizon the scalars settle to values determined by the charges carried by the black hole and independent of the values at infinity. It is so, because on the horizon the energy contained in vector fields acts as an effective potential (the black hole potential), driving the scalars towards its minima. For spherically symmetric black holes in theories where gauge potentials appear in the Lagrangian solely through field strengths, the attractor phenomenon can be alternatively described by a variational principle based on the so-called entropy function, defined as the Legendre transform with respect to electric fields of the Lagrangian density integrated over the horizon. Stationarity conditions for the entropy function then take the form of attractor equations relating the horizon values of the scalars to the black hole charges, while the stationary value itself yields the entropy of the black hole. In this study we examine the relationship between the entropy function and the black hole potential in four-dimensional N=2 supergravity and demonstrate that in the absence of higher-order corrections to the Lagrangian these two notions are equivalent. We also exemplify their practical application by finding a supersymmetric and a non-supersymmetric solution to the attractor equations for a conifold prepotential. Exploiting a connection between four- and five-dimensional black holes we then extend the definition of the entropy function to a class of rotating black holes in five-dimensional N=2 supergravity with cubic prepotentials, to which the original formulation did not apply because of broken spherical symmetry and explicit dependence of the Lagrangian on the gauge potentials in the Chern-Simons term. We also display two types of solutions to the respective attractor equations. The link between four- and five-dimensional black holes allows us further to derive five-dimensional first-order differential flow equations governing the profile of the fields from infinity to the horizon and construct non-supersymmetric solutions in four dimensions by dimensional reduction. Finally, four-dimensional extremal black holes in N=2 supergravity can be also viewed as certain two-dimensional string compactifications with fluxes. Motivated by this fact the recently proposed entropic principle postulates as a probability measure on the space of these string compactifications the exponentiated entropy of the corresponding black holes. Invoking the conifold example we find that the entropic principle would favor compactifications that result in infrared-free gauge theories.

M. Trigiante [Politecnico, Torino] Mirror-covariant formulation of N=2 supergravity from generalized Calabi-Yau compactifications [ Mon 12:00 pm ] Click To Play [ NOTE: quickstart=off, please wait for entire file (~40mb) to load, before it plays ]SlidesFlash 8 version:

This lecture is based on joint work in progress with H.Derksen and J.Weyman. We obtain a far-reaching generalization of classical Bernstein-Gelfand-Ponomarev reflection functors playing a fundamental role in the theory of quiver representations. These functors are defined only at a source or a sink of the quiver in question. We introduce a class of quivers with relations of a special kind given by non-commutative analogs of Jacobian ideals in the path algebra. We then define the mutations at arbitrary vertices for these quivers and their representations. If the vertex in question is a source or a sink, our mutations specialize to reflection functors. The motivations for this work come from several sources: superpotentials in physics, Calabi-Yau algebras, cluster algebras. We will keep the exposition elementary, with all necessary background explained from scratch.

As of now, string theory is the best candidate for a theory of quantum gravity. Since it is anomaly–free only in ten space-time dimensions, the six surplus spatial dimensions must be compactified. This thesis is concerned with the geometry of toroidal orbifolds and their applications in string theory. An orbifold is the quotient of a smooth manifold by a discrete group. In the present thesis, we restrict ourselves to orbifolds of the form T^6 /Z_N or T^6 /Z_N × Z_M . These so–called toroidal orbifolds are particularly popular as compactification manifolds in string theory. They present a good compromise between a trivial compactification manifold, such as the T^6 and one which is so complicated that explicit calculations are nearly impossible, which unfortunately is the case for many if not most Calabi–Yau manifolds. At the fixed points of the discrete group which is divided out, the orbifold develops quotient singularities. By resolving these singularities via blow–ups, one arrives at a smooth Calabi–Yau manifold. The systematic method to do so is explained in detail. Also the transition to the Orientifold quotient is explained. In string theory, toroidal orbifolds are popular because they combine the advantages of calculability and of incorporating many features of the standard model, such as non-Abelian gauge groups, chiral fermions and family repetition. In the second part of this thesis, applications in string phenomenology are discussed. The applications belong to the framework of compactifications with fluxes in type IIB string theory. Flux compactifications on the one hand provide a mechanism for supersymmetry breaking. One the other hand, they generically stabilize at least part of the geometric moduli. The geometric moduli, i.e. the deformation parameters of the compactification manifold correspond to massless scalar fields in the low energy effective theory. Since such massless fields are in conflict with experiment, mechanisms which generate a potential for them and like this fix the moduli to specific values must be investigated. After some preliminaries, two main examples are discussed. The first belongs to the category of model building, where concrete models with realistic properties are investigated. A brane model compactified on T^6 /Z_2 × Z_2 is discussed. The flux-induced soft supersymmetry breakingparameters are worked out explicitly. The second example belongs to the sub ject of moduli stabilization along the lines of the proposal of Kachru, Kallosh, Linde and Trivedi (KKLT). Here, in addition to the background fluxes, non-perturbative effects serve to stabilize all moduli. In a second step, a meta-stable vacuum with a small positive cosmological constant is achieved. Orientifold models which result from resolutions of toroidal orbifolds are discussed as possible candidate models for an explicit realization of the KKLT proposal. The appendix collects the technical details for all commonly used toroidal orbifolds and constitutes a reference book for these models.

In this thesis we investigate a large new class of four-dimensional supersymmetric string vacua defined as compactifications of the $E_8 times E_8$ and the $SO(32)$ heterotic string on smooth Calabi-Yau threefolds with unitary gauge bundles and heterotic five-branes. This opens up the way for phenomenologically interesting string compactifications on simply connected manifolds in that the conventional gauge symmetry breaking via Wilson lines is replaced by the embedding of non-flat line bundles into the ten-dimensional gauge group. The first part of the thesis discusses the implementation of this idea into the $E_8 times E_8$ heterotic string. After specifying a large class of group theoretic embeddings featuring unitary bundles, we analyse the effective four-dimensional ${cal N}=1$ supergravity upon compactification. The simultaneous presence of five-branes and abelian gauge groups requires the introduction of new anomaly cancelling counter terms into the effective action. These are also derived by an M-theory computation. The full set of Green-Schwarz terms allows for the extraction of the threshold corrections. From the gauge invariant K"ahler potential for the moduli fields we derive a modification of the Fayet-Iliopoulos D-terms arising at one-loop in string perturbation theory. From this we conjecture a one-loop deformation of the Hermitian Yang-Mills equation and introduce the idea of $lambda$-stability as the perturbatively correct stability concept generalising the notion of Mumford stability valid at tree-level. We then proceed to a definition of $SO(32)$ heterotic vacua with unitary gauge bundles in the presence of heterotic five-branes and find agreement of the resulting spectrum with the S-dual framework of Type I/Type IIB orientifolds. A similar analysis of the effective four-dimensional supergravity is performed. Further evidence for the proposed one-loop correction to the stability condition is found by identifying the heterotic corrections as the S-dual of the perturbative part of $Pi$-stability as the correct stability concept in Type IIB theory. After reviewing the construction of holomorphic stable vector bundles on elliptically fibered Calabi-Yau manifolds via spectral covers, we provide semi-realistic examples for $SO(32)$ heterotic vacua with Pati-Salam and MSSM-like gauge sectors. These can be viewed, by S-duality, as the generalisation of toroidal magnetized $D9$-branes to non-abelian braneworlds on genuine Calabi-Yau manifolds. We finally discuss the construction of realistic vacua with flipped $SU(5)$ GUT and MSSM gauge group within the $E_8 times E_8$ framework, based on the embedding of line bundles into both $E_8$ factors. Some of the appealing phenomenological properties of this stringy realisation of flipped $SU(5)$ models, in particular stability of the proton, are discussed. MSSM-like gauge coupling unification is possible for the threshold corrected gauge couplings. We explicitly construct a couple of supersymmetric string vacua in both setups with precisely the three observed chiral matter generations and without any exotic chiral states.

In this thesis the properties of D-branes on Calabi–Yau spaces are investigated. Compactifications of type II string theories on these spaces to which D-branes are added lead to N = 1 supersymmetric gauge theories on the world-volume of these D-branes. Both the Calabi–Yau spaces and the D-branes have in general a moduli space. We examine the dependence of the gauge theory on the choice of the moduli, in particular those of the K¨ahler structure of the Calabi–Yau manifold. For this purpose we choose two points in this moduli space which are distinguished by the fact that there exists an explicit description of the spectrum of the D-branes. One of these points corresponds to a manifold in the large volume limit on which the D-branes are described by classical geometry of vector bundles. At the other points the size of the manifold is smaller than its quantum fluctuations such that the classical geometry looses its meaning and has to be replaced by a conformal field theory. The Witten index in the open string sector is independent of the variation of these moduli and serves, together with mirror symmetry, as a tool to compare the two descriptions. We give an extensive and general presentation of these two descriptions for the class of Fermat hypersurfaces in weighted projective spaces. We explicitly carry out the comparison in many representative examples. Among them are manifolds admitting elliptic and K3-fibrations and manifolds whose moduli space can be embedded into the moduli space of another manifold. One main focus is on D4-branes, in particular on the dimension of their moduli space. Using the methods developed we are able to further confirm with our results the modified geometric hypothesis by Douglas. It essentially states that the properties of these D-branes or of these gauge theories can be determined partly by classical geometry, partly by mirror symmetry. A peculiarity of these gauge theories is the appearance of lines of marginal stability at which BPS states can decay. We show the existence of such lines in the framework of this class of Calabi–Yau spaces in two di®erent ways and discuss the connection to the formation of bound states. Of particular interest is the D0-brane whose appearance in this framework is explained.