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DTSTART;TZID=America/New_York:20260504T150000
DTEND;TZID=America/New_York:20260504T160000
DTSTAMP:20260506T204342
CREATED:20260126T190454Z
LAST-MODIFIED:20260430T170629Z
UID:10003880-1777906800-1777910400@cmsa.fas.harvard.edu
SUMMARY:Twisted D-branes and TQFTs valued in Calabi-Yau categories
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Surya Raghavendran\, Yale University \nTitle: Twisted D-branes and TQFTs valued in Calabi-Yau categories \nAbstract: Recently\, Bozec–Calaque–Scherotzke have articulated a noncommutative version of the AKSZ construction\, which associates to a smooth Calabi–Yau category a fully extended TQFT valued in a category of iterated Calabi–Yau cospans. In this talk\, I will study a class of examples of such theories which arise in the context of conjectures of Costello and Li\, which describe Type II strings in certain Ramond–Ramond backgrounds as topological strings. These TQFTs capture structural features of the BPS physics of D-branes that are universal in Chan–Paton factors. Conjecturally commutative limits of the values of such theories on closed manifolds can sometimes be geometrically quantized to yield algebraic structures with Hall-type products. Examples of this paradigm include CoHAs associated to complex 3-folds\, CoHAs attached to local systems on 3-manifolds\, and the categorified Hall algebras of Porta–Sala.
URL:https://cmsa.fas.harvard.edu/event/qft_5426/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-5.4.26.docx.edit_-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260427T150000
DTEND;TZID=America/New_York:20260427T160000
DTSTAMP:20260506T204342
CREATED:20260401T191402Z
LAST-MODIFIED:20260420T211652Z
UID:10003927-1777302000-1777305600@cmsa.fas.harvard.edu
SUMMARY:Higher current algebras and chiral algebras
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Charles Young (University of Hertfordshire) \nTitle: Higher current algebras and chiral algebras \nAbstract: Vertex algebras capture physicists’ notion of OPEs in chiral CFTs\, in complex dimension one. For various motivations\, one would like to have analogs of vertex algebras in higher dimensions. Chiral algebras\, in the sense of Beilinson-Drinfeld and Francis-Gaitsgory\, provide a natural framework here\, because they re-express the vertex algebra axioms (which are rather sui generis\, and therefore hard to generalize) as something more recognizable (a chiral algebra is a Lie algebra\, of a sort).\nI will review this\, and then go on to introduce a certain concrete model of the unit chiral algebra in higher dimensions. In higher dimensions one is forced to work up to coherent homotopy in some fashion; in this model it turns out to be in the mildest fashion one could hope for: namely\, one moves from Lie algebras to their homotopy analogs\, L-infinity algebras\, and from chiral algebras to homotopy chiral algebras in a sense introduced by Malikov-Schechtman.\nThe main tool in the talk will be a strict cdga model — the polysimplicial model — of derived global sections of the structure sheaf on configuration space. The hope is that this model will prove well-adapted to doing concrete calculations\, and in that direction\, I will gesture towards a homotopy version of the usual Arnold/Orlik-Solomon relations for broken circuits. \nThis is joint work with Zhengping Gui and Laura Felder and is based largely on the preprint 2506.09728 \n  \n 
URL:https://cmsa.fas.harvard.edu/event/qft_42726/
LOCATION:CMSA G102\, 20 Garden Street\, Cambridge\, MA\, 02138
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-4.27.26.docx-1-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260420T150000
DTEND;TZID=America/New_York:20260420T160000
DTSTAMP:20260506T204342
CREATED:20260210T203936Z
LAST-MODIFIED:20260420T142242Z
UID:10003899-1776697200-1776700800@cmsa.fas.harvard.edu
SUMMARY:Zigzags\, adjoints\, and bordisms
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Lorenzo Riva (Harvard CMSA) \nTitle: Zigzags\, adjoints\, and bordisms \nAbstract: We will learn how to freely add adjoints to a category using a combinatorial procedure which involves drawing zigzags of squares. Peculiarly\, we can use these to draw some bordisms. This is joint work with Martina Rovelli.
URL:https://cmsa.fas.harvard.edu/event/qft_4202026/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-4.20.26-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260406T150000
DTEND;TZID=America/New_York:20260406T160000
DTSTAMP:20260506T204342
CREATED:20260224T161017Z
LAST-MODIFIED:20260401T201808Z
UID:10003912-1775487600-1775491200@cmsa.fas.harvard.edu
SUMMARY:Twistorial constructions of higher genus integrability
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Seraphim Jarov\, Perimeter Institute \nTitle: Twistorial constructions of higher genus integrability \nAbstract: I will present a new method to engineer integrable models in 4d with higher genus spectral parameters. The method has a twistorial origin – by working on a branched covering of twistor space\, I show how one can derive deformations of holomorphic BF theory on twistor space which descend to elliptic and hyperelliptic models on R^4 via the Penrose transform. I show how one can bootstrap the Penrose transformed actions using symmetry and integrability to find deformations of self-dual Yang-Mills theory. I will also discuss some novel deformations of a BF type description of Hitchin’s equations. This is based on my paper: 2509.12486
URL:https://cmsa.fas.harvard.edu/event/qft_4626/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-4.6.26.docx.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260330T150000
DTEND;TZID=America/New_York:20260330T160000
DTSTAMP:20260506T204342
CREATED:20260126T190411Z
LAST-MODIFIED:20260325T163011Z
UID:10003879-1774882800-1774886400@cmsa.fas.harvard.edu
SUMMARY:K-theoretic stable envelopes\, quantum loop groups and wall-crossings
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Tianqin Zhu\, Columbia University \nTitle: K-theoretic stable envelopes\, quantum loop groups and wall-crossings \nAbstract: The stable envelope is an important tool in both geometric representation theory and the enumerative geometry. One of the most important application is that it generates the geometric quantum loop group via the FRT formalism. In this talk\, we will show that the geometric quantum loop group is isomorphic to the Drinfeld double given by the preprojective K-theoretic Hall algebra and the nilpotent K-theoretic Hall algebra. Moreover we will show a more refined result that the wall-crossing for the K-theoretic stable envelope is controlled by the universal R-matrix for the slope subalgebra of the Drinfeld double\, which leads to the isomorphism between the wall subalgebra in geometric quantum loop groups and the slope subalgebras in the Drinfeld double. If time permits\, I will talk about the recent progress of such isomorphism in the case of the critcial stable envelopes in both critical K-theory and critical cohomology. This is based on the work 2511.02161 \n 
URL:https://cmsa.fas.harvard.edu/event/qft_33026/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-3.30.26.docx.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260316T150000
DTEND;TZID=America/New_York:20260316T160000
DTSTAMP:20260506T204342
CREATED:20260224T160950Z
LAST-MODIFIED:20260311T180714Z
UID:10003911-1773673200-1773676800@cmsa.fas.harvard.edu
SUMMARY:Finite N indices from branes and negative branes
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Kasia Budzik (Harvard University) \nTitle: Finite N indices from branes and negative branes \nAbstract: Finite-N effects in large-N gauge theories\, such as trace relations\, are expected to be holographically dual to non-perturbative phenomena in string theory\, such as Giant Graviton branes. A convenient setting to study these effects are supersymmetric indices of U(N) gauge theories. The finite-N indices can be reproduced by a series of corrections to the infinite-N result\, known as the Giant Graviton expansion.\nIn this talk I will present a generalization of the Molien-Weyl formula computing generating functions of invariants of supergroups U(N|M)\, which arise as gauge groups of brane/negative brane systems in string theory. The formula leads to a new expansion relating finite-N and infinite-N indices of U(N) gauge theories. I will comment on its relation to Murthy’s Giant Graviton expansion and suggest a physical interpretation in terms of branes and negative branes. This talk is based on arXiv:2509.20451 and work in progress with Davide Gaiotto.
URL:https://cmsa.fas.harvard.edu/event/qft_31626/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-3.16.26.docx-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260309T150000
DTEND;TZID=America/New_York:20260309T160000
DTSTAMP:20260506T204342
CREATED:20260224T160904Z
LAST-MODIFIED:20260224T160904Z
UID:10003910-1773068400-1773072000@cmsa.fas.harvard.edu
SUMMARY:Quantum Field Theory and Physical Mathematics
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Davide Gaiotto (Perimeter Institute)
URL:https://cmsa.fas.harvard.edu/event/qft_3926-2/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260209T150000
DTEND;TZID=America/New_York:20260209T160000
DTSTAMP:20260506T204342
CREATED:20251223T185635Z
LAST-MODIFIED:20260203T185733Z
UID:10003839-1770649200-1770652800@cmsa.fas.harvard.edu
SUMMARY:On the p-curvature of quantum connections of CY threefolds
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Shaoyun Bai (MIT) \nTitle: On the p-curvature of quantum connections of CY threefolds \nAbstract: The small quantum connection of Calabi-Yau varieties has integral coefficients\, thus admits reduction mod a prime number p. A fundamental invariant associated with flat connections over characteristic p is the p-curvature\, which lies at the heart of study of algebraic differential equations. I will explain how to identify the p-curvature of quantum connection of any compact Calabi-Yau threefold with the quantum Steenrod operation\, thereby providing a modular description of the p-curvature in this setting. I will also discuss the role of BPS invariants and the mirror symmetry context. This is based on joint work with Jae Hee Lee.
URL:https://cmsa.fas.harvard.edu/event/qft_2926/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
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END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20260202T150000
DTEND;TZID=America/New_York:20260202T160000
DTSTAMP:20260506T204342
CREATED:20251223T185600Z
LAST-MODIFIED:20260126T185935Z
UID:10003816-1770044400-1770048000@cmsa.fas.harvard.edu
SUMMARY:Reflexive Polytopes and the Convergence of Feynman Integrals
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Pierre Vanhove (Institute of Theoretical Physics – Saclay) \nTitle: Reflexive Polytopes and the Convergence of Feynman Integrals \nAbstract: In the parametric representation\, Feynman integrals can be viewed as Euler integrals defined by the Symanzik polynomials of a graph. The convergence properties of these integrals are intimately tied to the combinatorial geometry of their associated Newton polytopes; specifically\, finiteness is guaranteed when the polytope contains interior points. We present a classification of Feynman integrals associated with polytopes containing a unique interior point\, identifying a subset that are reflexive. Our results show that such reflexive polytopes are surprisingly scarce within the space of Feynman graphs. We conclude by computing several infinite families of these integrals and exploring their connections to mirror symmetry and toric geometry. This is based on joint work with Leonardo de la Cruz and Pavel Novichkov.
URL:https://cmsa.fas.harvard.edu/event/qft_2226/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-2.2.26-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20251208T150000
DTEND;TZID=America/New_York:20251208T160000
DTSTAMP:20260506T204342
CREATED:20251202T152832Z
LAST-MODIFIED:20251202T160431Z
UID:10003841-1765206000-1765209600@cmsa.fas.harvard.edu
SUMMARY:Computing WKB periods 
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Max Meynig\, University of Connecticut \nTitle: Computing WKB periods \nAbstract:  In one dimensional quantum mechanics\, the all-orders WKB method leads to ‘quantum periods’ which are formal power series in \hbar whose coefficients are certain period integrals. These periods\, which limelight in supersymmetric/string theories\, have rich structure and can be computed in a number of ways. I will discuss a new perspective on them and their computation.
URL:https://cmsa.fas.harvard.edu/event/qft_12825/
LOCATION:CMSA Room G02\, 20 Garden Street\, Cambridge\, MA\, 02138
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-12.8.25.docx-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20251117T150000
DTEND;TZID=America/New_York:20251117T160000
DTSTAMP:20260506T204342
CREATED:20251014T143757Z
LAST-MODIFIED:20251112T173007Z
UID:10003815-1763391600-1763395200@cmsa.fas.harvard.edu
SUMMARY:BV and the ThimTFT
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Justin Kulp\, Stony Brook \nTitle: BV and the ThimTFT \nAbstract: The SymTFT (or “quiche”) construction relates different global forms of d-dimensional QFTs with discrete symmetry: realizing different global forms as a (d+1)-dimensional TFT on an interval\, with a common “physical” boundary condition on one side\, and different topological boundary conditions on the other. In my talk\, I will describe an analogue of the SymTFT which relates theories with the same “perturbative equations of motion”\, but different non-perturbative completions.\nI will start with a lightning overview of conformal blocks and relative QFT\, then explain the BV formalism in some detail—focusing on the elegant (super)geometric story in 0d for simplicity. I will argue that there is a natural 1d cohomological TFT (called the ThimTFT) associated to the classical action S\, with different topological boundary conditions described by convergent path-integral contours in a complexified field space. Time permitting\, I will discuss extensions to higher dimensions. Based on WIP.
URL:https://cmsa.fas.harvard.edu/event/qft_111725/
LOCATION:CMSA Room G02\, 20 Garden Street\, Cambridge\, MA\, 02138
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-11.17.25.docx-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20251110T150000
DTEND;TZID=America/New_York:20251110T160000
DTSTAMP:20260506T204342
CREATED:20251014T143715Z
LAST-MODIFIED:20251103T155540Z
UID:10003814-1762786800-1762790400@cmsa.fas.harvard.edu
SUMMARY:The Moyal bracket and the BV cohomology of the spinning particle
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Ezra Getzler\, Northwestern \nTitle: The Moyal bracket and the BV cohomology of the spinning particle \nAbstract: The spinning particle is the one-dimensional reduction of the Neveu-Schwartz-Ramond superstring. It consists of a supersymmetric particle moving in a one-dimensional supergravity background\, and its quantization is the Hilbert superspace of harmonic spinors. (These models are classified by N\, the number of copies of fermionic fields. In this talk\, N=1. The extension to N=2 is work in progress with Ivo.) It is actually an AKSZ model (so a generalization of one-dimensional Chern-Simons)\, and so associated to a differential graded symplectic supermanifold\, by which we mean a pair (ω\,Q)\, where ω is a(n exact) symplectic form and Q is an odd function of degree 1. The cohomology of the ring of functions of this supermanifold with differential the Poisson bracket  with Q determines the classical BV cohomology of the spinning particle\, so is important for understanding perturbative BV quantization of this model. I calculated this cohomology in earlier work for N=1\, and showed that it is somewhat bizarre\, with two series of cohomology classes in arbitrary negative degrees\, each a copy of the functions on the target manifold. \nIn the study of quantum BFV\, we should instead consider the Moyal bracket on the target\, and lift Q to an element Q satisfying [Q\,Q]=0. The cohomology of the differential [Q\,-] is the Moyal cohomology of the differential graded symplectic supermanifold. (This lift corresponds to the choice of a Spinc structure on the target manifold.) In this talk\, I prove that the Moyal cohomology\, unlike the Poisson cohomology\, is well-behaved: in the spectral sequence from Poisson to Moyal cohomology\, the extra cohomology classes of negative degree cancel each other pairwise at the E1 page. \n 
URL:https://cmsa.fas.harvard.edu/event/qft_111025/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
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END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20251027T150000
DTEND;TZID=America/New_York:20251027T160000
DTSTAMP:20260506T204342
CREATED:20250924T183029Z
LAST-MODIFIED:20251024T144939Z
UID:10003798-1761577200-1761580800@cmsa.fas.harvard.edu
SUMMARY:de Rham Theory in Derived Differential Geometry
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Grigorii Taroian\, U Toronto \nTitle: de Rham Theory in Derived Differential Geometry \nAbstract: In the talk\, I will describe recent progress in building a version of de Rham theory for derived manifolds and derived differentiable stacks.\nDerived differential geometry is a nascent field applying techniques from derived algebraic geometry to the study of spaces with smooth structures. As such\, it serves as a natural home for studying objects arising in BV formalism. For instance\, concepts such as critical loci of action functionals or their quotients by gauge actions can be naturally interpreted as derived differentiable stacks.\nIn our work\, we build a version of de Rham theory for these spaces and prove a version of the de Rham isomorphism. Due to the highly singular nature of all objects involved\, developing such a theory is significantly more challenging than in the usual differential geometry\, and thus\, we construct our formalism with inspiration from algebraic geometry rather than classical differential topology. As a main application of the developed theory\, we obtain a version of the comparison morphism between de Rham and constant sheaf cohomology arising from the corresponding map of stacks. This should enable further developments\, with a view towards a fully-fledged theory of shifted symplectic structures for derived differentiable stacks.\nThe talk is based on a preprint of the same name\, arXiv:2505.03978.
URL:https://cmsa.fas.harvard.edu/event/qft_102725/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
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END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20251020T150000
DTEND;TZID=America/New_York:20251020T160000
DTSTAMP:20260506T204342
CREATED:20250924T183004Z
LAST-MODIFIED:20251016T160042Z
UID:10003797-1760972400-1760976000@cmsa.fas.harvard.edu
SUMMARY:Categorical 't Hooft expansion and Chiral Algebras
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Adrian López-Raven\, Perimeter \nTitle: Categorical ‘t Hooft expansion and Chiral Algebras \nAbstract: In https://arxiv.org/abs/2411.00760\, we show how holographic dual B-model backgrounds can be systematically derived from the ‘t Hooft expansion of specific families of chiral algebras. The resulting holographic dual backgrounds are typically non-commutative and appear to be novel. In this talk I’ll review certain aspects of our construction. In particular\, we’ll review how to build a category of D-branes for the String Theory dual\, starting from the planar limit of the chiral algebra. Given its generality\, I’ll emphasize the potential utility of the construction in the study of weak coupling holography for general theories with a large N limit. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/qft_102025/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-10.20.25-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20251006T150000
DTEND;TZID=America/New_York:20251006T160000
DTSTAMP:20260506T204342
CREATED:20250924T182709Z
LAST-MODIFIED:20251006T144221Z
UID:10003796-1759762800-1759766400@cmsa.fas.harvard.edu
SUMMARY:Non-perturbative aspects of self-dual gauge theory
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Kevin Costello (Perimeter Institute)\n\nTitle: Non-perturbative aspects of self-dual gauge theory\n\nAbstract: Self-dual gauge theory is conformal in perturbation theory\, but has a non-trivial beta-function when instanton effects are included. I will give two computations of this beta-function\, one based on the Grothendieck-Riemann-Roch formula and one using holography in the topological string.   This leads to two new ways to compute the standard QCD beta-function at one loop\, without using Feynman diagrams.  If time permits\, I will also discuss how instantons effect scattering amplitudes.\n\n 
URL:https://cmsa.fas.harvard.edu/event/qft_100625/
LOCATION:Virtual
CATEGORIES:Quantum Field Theory and Physical Mathematics
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END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250929T150000
DTEND;TZID=America/New_York:20250929T160000
DTSTAMP:20260506T204342
CREATED:20250924T181258Z
LAST-MODIFIED:20250924T183325Z
UID:10003795-1759158000-1759161600@cmsa.fas.harvard.edu
SUMMARY:Graph integrals on Kahler manifolds
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Minghao Wang\, Boston University \nTitle: Graph integrals on Kahler manifolds \nAbstract: I will talk about my recent work with Junrong Yan. We proved the convergence of Graph integrals on analytic Kahler manifolds in the sense of Cauchy principal values\, which are originally from holomorphic quantum field theories. In particular\, this allows us to construct geometric invariants of Calabi-Yau metrics. I will also talk about some potential applications of our results. References: arXiv:2507.09170\, arXiv:2401.08113
URL:https://cmsa.fas.harvard.edu/event/qft_92925/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-9.29.25-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250922T150000
DTEND;TZID=America/New_York:20250922T160000
DTSTAMP:20260506T204342
CREATED:20250826T190916Z
LAST-MODIFIED:20250917T134457Z
UID:10003761-1758553200-1758556800@cmsa.fas.harvard.edu
SUMMARY:Non-Supersymmetric Orbifolds\, Quivers and Chen-Ruan Orbifold Cohomology
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Max Hübner (Uppsala & CMSA) \nTitle: Non-Supersymmetric Orbifolds\, Quivers and Chen-Ruan Orbifold Cohomology \nAbstract: We consider D3-brane probes of non-supersymmetric orbifolds and IIA on the same class of non-supersymmetric orbifolds. Both setups are characterized\, in part\, by quivers (which in the latter case relate for example to D0-brane probes) from which symmetries constraining the scale-dependence and tachyonic instabilities of the two systems\, respectively\, can be derived. We demonstrate that these considerations can be matched via a geometric analysis of the asymptotic boundary of the relevant orbifolds\, in all cases\, via considerations centered on Chen-Ruan orbifold cohomology.
URL:https://cmsa.fas.harvard.edu/event/qft_92225/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-9.22.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250915T150000
DTEND;TZID=America/New_York:20250915T160000
DTSTAMP:20260506T204342
CREATED:20250910T193835Z
LAST-MODIFIED:20250910T194841Z
UID:10003788-1757948400-1757952000@cmsa.fas.harvard.edu
SUMMARY:Orientifolds for F-theory on K3 Surfaces
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Chuck Doran (Alberta/CMSA) \nTitle: Orientifolds for F-theory on K3 Surfaces \nAbstract: Compactification of F-theory on an elliptically fibered K3 surface provides a framework to encode type IIB string theory on elliptic curves\, with the Kaehler modulus of the elliptic curve encoded in the complex structure of the elliptic fibers. In work with Malmendier\, Mendez-Diez\, and Rosenberg we extend that perspective by examining F-theory orientifolds on elliptically fibered K3 surfaces and connecting them to D-brane classifications using real K-theory (KR-theory).  The real structures—antiholomorphic involutions—on our K3 surfaces connect the geometry with the physics\, providing a natural setting for understanding the interplay between elliptic fibration structures and D-brane classifications in F-theory. We construct Real normal forms with their associated antiholomorphic involutions and use this to make explicit the 2-torsion Brauer twist that relates our normal forms to the Jacobian (Weierstrass normal form) elliptic fibration\, including the realization of a representative for the twisting class as an Azumaya algebra. This all connects back to the physics by considering three families of real K3 surfaces whose string limits give the three different type IIB theories on P1 with four type I_0^∗ Kodaira fibers.
URL:https://cmsa.fas.harvard.edu/event/qft_91525/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-9.15.25-scaled.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250512T150000
DTEND;TZID=America/New_York:20250512T160000
DTSTAMP:20260506T204342
CREATED:20250226T174007Z
LAST-MODIFIED:20250605T134144Z
UID:10003716-1747062000-1747065600@cmsa.fas.harvard.edu
SUMMARY:An index for 2d invertible phases of quantum many-body systems
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Nikita Sopenko\, IAS \nTitle: An index for 2d invertible phases of quantum many-body systems
URL:https://cmsa.fas.harvard.edu/event/qft_51225/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-5.12.25-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250505T150000
DTEND;TZID=America/New_York:20250505T160000
DTSTAMP:20260506T204342
CREATED:20250226T173940Z
LAST-MODIFIED:20250226T173940Z
UID:10003715-1746457200-1746460800@cmsa.fas.harvard.edu
SUMMARY:Quantum Field Theory and Physical Mathematics
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar
URL:https://cmsa.fas.harvard.edu/event/qft_5525/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250414T150000
DTEND;TZID=America/New_York:20250414T160000
DTSTAMP:20260506T204342
CREATED:20250128T192515Z
LAST-MODIFIED:20250409T174327Z
UID:10003695-1744642800-1744646400@cmsa.fas.harvard.edu
SUMMARY:The Extended Vertex Algebra of 4d N = 2 SCFTs and their Higher Products
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Mitch Weaver\, KAIST \nTitle: The Extended Vertex Algebra of 4d N = 2 SCFTs and their Higher Products \nAbstract: Every 4d N=2 superconformal field theory contains a BPS protected sub-algebra of local operators that has the structure of a vertex operator algebra (VOA). This VOA is identified by passing to the cohomology of a nilpotent supercharge\, T\, whose local operator cohomology is represented by twist-translated Schur operators with support in a Euclidean two-plane. When working in 4d Minkowski space\, this cohomology admits a web of three extended operators (called descent operators) that are constructed from each Schur operator in the VOA\, have worldvolume support in the Lorentzian two-plane that is transverse to the Euclidean plane supporting the VOA\, and behave as point-like insertions in the plane of the VOA\, i.e. as new chiral operators. The combined result is the extended vertex algebra (EVA): a universal extension of the VOA that canonically has the structure of a quasi-VOA\, i.e. a vertex algebra (VA) with no conformal vector but which still possesses a representation of sl(2). After reviewing the VOA of Schur operators\, I will explain the origin of the descent operators and present the OPEs for a subsector of the EVA in the free hyper SCFT.\nTime permitting\, I will also describe the construction and basic properties of a set of higher products that are associated to each descent operator. Such products function as higher dimensional versions of 2d chiral algebra λ-brackets\, i.e. positive mode operators: they are defined on the EVA and map to the operators appearing in the singular terms of OPEs involving descent operators. Their existence offers a route toward sl(2) symmetry enhancement of the EVA and suggests the latter has structural properties that are common to the higher dimensional chiral algebras describing the minimal twists of 3d N = 2 and 4d N = 1 SQFTs. This talk is based on [2211.04410] and forthcoming work.
URL:https://cmsa.fas.harvard.edu/event/qft_41425/
LOCATION:Hybrid – G10
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-4.14.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250407T150000
DTEND;TZID=America/New_York:20250407T160000
DTSTAMP:20260506T204342
CREATED:20250128T192454Z
LAST-MODIFIED:20250331T184600Z
UID:10003694-1744038000-1744041600@cmsa.fas.harvard.edu
SUMMARY:Quantum Field Theory and Physical Mathematics
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Matthew Yu (Oxford) \nTitle: A new tangential structure for type IIA string theory \nAbstract: The Green-Schwarz anomaly cancellation condition says that the target space of heterotic string theory must come with a string structure for the theory to be consistent. In this talk we discuss a new tangential structure called string^h\, first introduced by Devalapurkar\, as a spin^c analogue of string. Approximating the correct tangential structure of string theory has many implications\, primarily is the Swampland program via the cobordism conjecture of Mcnamara and Vafa. We will show that the spectrum of string^h has the notable property that it orients tmf_1(n)\, just like how the spectrum of string orients tmf\, by the work of Ando-Hopkins-Rezk. Finally we will show that the anomaly condition of the partition function of M-theory\, studied by Diaconescu-Moore-Witten is implied by a string^h structure on the target space of type IIA\, in parallel to the Green-Schwarz anomaly for heterotic string theory\, and discuss applications for anomaly cancellation.
URL:https://cmsa.fas.harvard.edu/event/qft_4725/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-4.7.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250331T150000
DTEND;TZID=America/New_York:20250331T160000
DTSTAMP:20260506T204342
CREATED:20250128T192422Z
LAST-MODIFIED:20250326T181346Z
UID:10003693-1743433200-1743436800@cmsa.fas.harvard.edu
SUMMARY:Homotopical Methods for Free and Interacting Fermionic SPTs
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Cameron Krulewski\, MIT \nTitle: Homotopical Methods for Free and Interacting Fermionic SPTs \nAbstract: We develop and compute homotopical “free-to-interacting maps” to compare classifications of fermionic symmetry-protected topological phases (SPTs)\, determining when such phases are stable under interactions or\, alternatively\, interaction-enabled. Generalizing work of Freed-Hopkins\, we construct maps from K-theory to Anderson-dual spin bordism in two new situations: for weak phases\, which are SPTs protected by discrete translation symmetry\, and for the “Bott spiral” studied by Queiroz-Khalaf-Stern\, who observed that the tenfold way classification of free theories breaks down to a large 2-torsion interacting classification. Along the way\, we employ T-duality\, generalizations of the spin orientation of KO-theory\, and the Adams spectral sequence. \nThis talk is based on joint work with Omar Antolín Camarena\, Arun Debray\, Natalia Pacheco-Tallaj\, Daniel Sheinbaum\, and Luuk Stehouwer.
URL:https://cmsa.fas.harvard.edu/event/qft_33125/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-3.31.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250324T150000
DTEND;TZID=America/New_York:20250324T160000
DTSTAMP:20260506T204342
CREATED:20250128T192400Z
LAST-MODIFIED:20250318T141044Z
UID:10003692-1742828400-1742832000@cmsa.fas.harvard.edu
SUMMARY:The Andersen-Kashaev volume conjecture for FAMED geometric triangulations  
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Ka Ho Wong (Yale) \nTitle: The Andersen-Kashaev volume conjecture for FAMED geometric triangulations \nAbstract: In the early 2010s\, Andersen and Kashaev defined a TQFT based on quantum Teichmuller theory. In particular\, they define a partition function for every ordered ideal triangulation of hyperbolic knot complement in $\mathbb{S}^3$ equipped with an angle structure. The Andersen-Kashaev volume conjecture suggests that the partition function can be expressed in terms of a Jones function of the knot which\, in its semi-classical limit\, decay exponentially with decay rate the hyperbolic volume of the knot complement. In this talk\, we will introduce a purely combinatorial condition on triangulations which\, together with the geometricity of the triangulations\, imply the Andersen-Kashaev volume conjecture and its generalization. This talk is based on the joint work with Fathi Ben Aribi.
URL:https://cmsa.fas.harvard.edu/event/qft_32425/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-3.24.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250310T150000
DTEND;TZID=America/New_York:20250310T160000
DTSTAMP:20260506T204342
CREATED:20250128T192310Z
LAST-MODIFIED:20250303T211818Z
UID:10003691-1741618800-1741622400@cmsa.fas.harvard.edu
SUMMARY:Comments on Non-Invertible Symmetries in K3 CFTs and the Conway Moonshine Module
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Sarah Harrison\, Northeastern \nTitle: Comments on Non-Invertible Symmetries in K3 CFTs and the Conway Moonshine Module \nAbstract: There is an established connection between discrete symmetry groups of K3 non-linear sigma models and a distinguished N=1 chiral SCFT called the Conway moonshine module. More specifically\, all symmetry groups of K3 NLSMs preserving the N=4 superconformal algebra can be obtained as subgroups of “Conway zero”\, the group of symmetries of the Conway module\, and their explicit action on the BPS spectrum can (almost always) be obtained via traces in the Conway module. A natural question is whether this relation extends to fusion category symmetry of these theories. I will discuss positive evidence in this direction\, by exploring examples of non-invertible topological defect lines in K3 NLSMs and the Conway module. This is based on work in progress with R. Angius\, S. Giaccari\, and R. Volpato.
URL:https://cmsa.fas.harvard.edu/event/qft_31025/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-3.10.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250303T150000
DTEND;TZID=America/New_York:20250303T160000
DTSTAMP:20260506T204342
CREATED:20250128T192248Z
LAST-MODIFIED:20250226T192433Z
UID:10003690-1741014000-1741017600@cmsa.fas.harvard.edu
SUMMARY:Quantum Field Theory and Physical Mathematics
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Kai Xu\, Harvard \nTitle: Finite Landscape of 6d N=(1\,0) Supergravity \nAbstract: We present a bottom-up argument showing that the number of massless fields in six-dimensional quantum gravitational theories with eight supercharges is uniformly bounded. Specifically\, we show that the number of tensor multiplets is bounded by T≤193\, and the rank of the gauge group is restricted to r(V)≤480. Given that F-theory compactifications on elliptic CY 3-folds are a subset\, this provides a bound on the Hodge numbers of elliptic CY 3-folds: h1\,1(CY3)≤491\, h1\,1(Base)≤194 which are saturated by special elliptic CY 3-folds. This establishes that our bounds are sharp and also provides further evidence for the string lamppost principle.
URL:https://cmsa.fas.harvard.edu/event/qft_3325/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-3.3.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250224T150000
DTEND;TZID=America/New_York:20250224T160000
DTSTAMP:20260506T204342
CREATED:20250128T192220Z
LAST-MODIFIED:20250220T192557Z
UID:10003689-1740409200-1740412800@cmsa.fas.harvard.edu
SUMMARY:Toward constructing a large-scale quantum computer based on TQFT
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Liyuan Chen ( Harvard) \nTitle: Toward constructing a large-scale quantum computer based on TQFT \nAbstract: Topological quantum computation\, motivated by topological quantum field theory (TQFT)\, offers a promising path toward fault-tolerant universal quantum computation. However\, the practical realization of such a system remains challenging due to the difficulty of finding suitable topological materials. In this work\, we provide a comprehensive blueprint for constructing a fault-tolerant universal quantum computer based on the quantum double model $\mathcal{D}(S_3)$\, a specific non-Abelian topological order. We implement logical computations using quantum circuits on qubits and qutrits\, including a single non-Clifford gate\, compatible with near-term quantum devices. This work bridges the gap between abstract mathematical frameworks and noise-resilient quantum computation on near-term devices. Our proposal offers a promising path to realize a non-Abelian anyon-based large scale quantum computer.
URL:https://cmsa.fas.harvard.edu/event/qft_22425/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/1740079272812-56d7a2d6-da58-4464-8ade-b9b1856de79025_1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250210T110000
DTEND;TZID=America/New_York:20250210T120000
DTSTAMP:20260506T204342
CREATED:20250128T192122Z
LAST-MODIFIED:20250203T191001Z
UID:10003687-1739185200-1739188800@cmsa.fas.harvard.edu
SUMMARY:On 5d conformal matter
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Mario De Marco (UL Brussels) \nTitle: On 5d conformal matter \nAbstract: SCFTs with 8 supercharges lie at the sweet spot of the classification program of susy scale-invariant theories: with this amount of susy\, the classification is in principle achievable\, despite being non-trivial. In this talk\, I will present the geometric approach to the classification of 5d SCFTs\, based on geometric engineering on non-compact Calabi-Yau manifolds. The strategy is to imagine a 5d SCFT as a non-Lagrangian generalization of a quiver\, and to build this generalised quiver by gauging together indecomposable blocks\, called  “5d conformal matter theories”. In this talk\, I will start with a recap of the geometric construction of [2311.04984]. I will then present some forthcoming results\, concerning the (p\,q) web realization of 5d conformal matter theories\, their reduction to 4d\, their magnetic quiver\, and the discovery of exotic “trifundamental” and “quadrifundamental” 5d indecomposable blocks (with flavor group at least SO(4k+2)^3 or SO(4k)^4). \nIn collaboration with M. Del Zotto\, M. Graffeo\, J. Grimminger\, and A. Sangiovanni. \n 
URL:https://cmsa.fas.harvard.edu/event/qft_21025/
LOCATION:Virtual
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-2.10.25-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250203T150000
DTEND;TZID=America/New_York:20250203T160000
DTSTAMP:20260506T204342
CREATED:20250124T171714Z
LAST-MODIFIED:20250131T150210Z
UID:10003672-1738594800-1738598400@cmsa.fas.harvard.edu
SUMMARY:Topological to Gravitational Leptogenesis\, via Ultra Unification 
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Juven Wang (LIMS\, Royal Institution) \nTitle: Topological to Gravitational Leptogenesis\, via Ultra Unification \nAbstract: We propose a new mechanism for leptogenesis\, named Topological Leptogenesis\, in which dark matter consists of topological order\, so gapped anyon excitations decay to generate the Standard Model lepton asymmetry. Topological Leptogenesis is in contrast with the Majorana Leptogenesis and Gravitational Leptogenesis. In the standard Majorana Leptogenesis\, the baryon asymmetry of the present universe is attributed to the leptogenesis from the sterile right-handed neutrino with heavy Majorana fermion mass decaying into the Standard Model leptons in the very early universe\, while the electroweak sphaleron causes baryogenesis at a later time. Gravitational leptogenesis can be regarded as an intermediate step between Majorana particle leptogenesis and topological non-particle leptogenesis. Topological Leptogenesis is derived out of Ultra Unification constructed from a mod 16 nonperturbative global anomaly cancellation that adds a symmetry-extended anomalous gapped topological quantum field theory (TQFT) to the Standard Model. Thus (1) the Beyond-the-Standard-Model (BSM) Dark Matter partly consists of Topological Order with low energy TQFT\, while there are anyon string excitations above the energy gap. (2) The 5th force is a Topological Discrete Gauge Force of (B-L) that mediates between the Standard Model particles\, the BSM Topological Order\, and gapped anyon string non-particle excitations. \nBased on https://arxiv.org/abs/2501.00607\, https://arxiv.org/abs/2012.15860\, https://arxiv.org/abs/2302.14862 and https://arxiv.org/abs/2411.05786.
URL:https://cmsa.fas.harvard.edu/event/qft_2325/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-2.3.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250127T150000
DTEND;TZID=America/New_York:20250127T160000
DTSTAMP:20260506T204342
CREATED:20240907T194212Z
LAST-MODIFIED:20250124T171827Z
UID:10003471-1737990000-1737993600@cmsa.fas.harvard.edu
SUMMARY:A homotopy of 2d SCFTs and an implication for Topological Modular Forms
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Vivek Saxena (YITP Stony Brook and NHETC Rutgers) \nTitle: A homotopy of 2d SCFTs and an implication for Topological Modular Forms \nAbstract: The Segal-Stolz-Teichner conjecture states that there exists an isomorphism between deformation classes of two-dimensional N=(0\,1) superconformal field theories (SCFTs) and generalized cohomology classes known as Topological Modular Forms (TMFs). Such 2d N=(0\,1) SCFTs arise naturally in physics as worldsheet theories of (possibly compactified) heterotic strings. Recently\, this connection was used to prove the absence of global anomalies in heterotic string theories and make predictions about topological terms in their low-energy effective actions\, among other things. \nIn this talk\, after giving a brief overview of these ideas\, I will describe a physics ”proof” (using methods from 2d CFT) of a mathematical conjecture of Tachikawa and Yamashita about TMF classes in degree 31. Specifically\, by examining the two worldsheet theories corresponding to two T-dual nine-dimensional spacetime non-supersymmetric heterotic string theories (namely the $(E_8)_1 \times (E_8)_1$ theory and the $(E_8)_2$ theory)\, I will argue that the $(E_8)_2$ theory corresponds to the unique nontrivial torsion element $[(E_8)_2]$ of TMF$^{31}$ with zero mod-2 elliptic genus.
URL:https://cmsa.fas.harvard.edu/event/qft_12725/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-1.27.25.png
END:VEVENT
END:VCALENDAR