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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231204T103000
DTEND;TZID=America/New_York:20231204T113000
DTSTAMP:20260501T213913
CREATED:20240222T065433Z
LAST-MODIFIED:20240222T152910Z
UID:10002786-1701685800-1701689400@cmsa.fas.harvard.edu
SUMMARY:CM-minimizers and standard models of Fano fibrations over curves
DESCRIPTION:Algebraic Geometry in String Theory Seminar \n\nSpeaker: Maksym Fedorchuk (Boston College) \nTitle: CM-minimizers and standard models of Fano fibrations over curves \nAbstract: A recent achievement in K-stability of Fano varieties is an algebro-geometric construction of a projective moduli space of K-polystable Fanos. The ample line bundle on this moduli space is the CM line bundle of Tian. One of the consequences of the general theory is that given a family of K-stable Fanos over a punctured curve\, the polystable filling is the one that minimizes the degree of the CM line bundle after every finite base change. A natural question is to ask what are the CM-minimizers without base change. In answering this question\, we arrive at a theory of Koll\’ar stability for fibrations over one-dimensional bases\, and standard models of Fano fibrations. I will explain the joint work with Hamid Abban and Igor Krylov in which we show that the CM-minimizers for del Pezzo fibrations are Corti’s standard models and related work in progress on quartic threefold hypersurfaces. \n\n 
URL:https://cmsa.fas.harvard.edu/event/agst-12423/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/CMSA-AGIST-12.04.23-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231113T103000
DTEND;TZID=America/New_York:20231113T113000
DTSTAMP:20260501T213913
CREATED:20240222T070558Z
LAST-MODIFIED:20240222T070558Z
UID:10002787-1699871400-1699875000@cmsa.fas.harvard.edu
SUMMARY:Stacky small resolutions of determinantal octic double solids and noncommutative Gopakumar-Vafa invariants
DESCRIPTION:Algebraic Geometry in String Theory Seminar \n\nSpeaker: Sheldon Katz\, UIUC \nTitle: Stacky small resolutions of determinantal octic double solids and noncommutative Gopakumar-Vafa invariants \nAbstract:  A determinantal octic double solid is the double cover X of P^3 branched along the degree 8 determinant of a symmetric matrix of homogeneous forms on P^3.  These X are nodal CY threefolds which do not admit a projective small resolution.  B-model techniques can be applied to compute GV invariants up to g \le 32.  This raises the question: what is the geometric meaning of these invariants? \nEvidence suggests that these enumerative invariants are associated with moduli stacks of coherent sheaves of modules over a sheaf B of noncommutative algebras on X constructed by Kuznetsov.  One of these moduli stacks is a stacky small resolution X’ of X itself.  This leads to another geometric interpretation of the invariants as being associated with moduli of sheaves on X’ twisted by a Brauer class.  Geometric computations based on these working definitions always agree with the B-model computations. \nThis talk is based on joint work with Albrecht Klemm\, Thorsten Schimannek\, and Eric Sharpe. \n\n 
URL:https://cmsa.fas.harvard.edu/event/agst-111323/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-11.13.2023.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231106T103000
DTEND;TZID=America/New_York:20231106T113000
DTSTAMP:20260501T213913
CREATED:20240222T071857Z
LAST-MODIFIED:20240222T152725Z
UID:10002788-1699266600-1699270200@cmsa.fas.harvard.edu
SUMMARY:Deformations of Landau-Ginzburg models and their fibers
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Andrew Harder\, Lehigh University \nTitle: Deformations of Landau-Ginzburg models and their fibers \nAbstract: In mirror symmetry\, the dual object to a Fano variety is a Landau-Ginzburg model. Broadly\, a Landau-Ginzburg model is quasi-projective variety Y with a superpotential function w\, but not all such pairs correspond to Fano varieties under mirror symmetry\, so a very natural question to ask is: Which Landau-Ginzburg models are mirror to Fano varieties? In this talk\, I will discuss a cohomological characterization of mirrors of (semi-)Fano varieties\, focusing on the case of threefolds. I’ll discuss how this characterization relates to the deformation and Hodge theory of (Y\,w)\, and in particular\, how the classification of (semi-)Fano threefolds is related to questions about moduli spaces of lattice polarized K3 surfaces.
URL:https://cmsa.fas.harvard.edu/event/agst-11623/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-11.06.2023.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230407T120000
DTEND;TZID=America/New_York:20230407T130000
DTSTAMP:20260501T213913
CREATED:20230825T085705Z
LAST-MODIFIED:20240122T075759Z
UID:10001304-1680868800-1680872400@cmsa.fas.harvard.edu
SUMMARY:Modular graph forms and iterated integrals in string amplitudes
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Oliver Schlotterer (Uppsala University) \nTitle: Modular graph forms and iterated integrals in string amplitudes \nAbstract: I will discuss string amplitudes as a laboratory for special functions and period integrals that drive fruitful cross-talk with particle physicists and mathematicians. At genus zero\, integration over punctures on a disk or sphere worldsheet generates multiple zeta values in the low-energy expansion of open- and closed-string amplitudes. At genus one\, closed-string amplitudes introduce infinite families of non-holomorphic modular forms through the integration over torus punctures known as modular graph forms. The latter inspired Francis Brown’s alternative construction of non-holomorphic modular forms in the mathematics literature via iterated integrals\, and I will report on recent progress in clarifying their connection with modular graph forms.
URL:https://cmsa.fas.harvard.edu/event/agst-4723/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230403T100000
DTEND;TZID=America/New_York:20230403T110000
DTSTAMP:20260501T213913
CREATED:20230825T085504Z
LAST-MODIFIED:20240228T081746Z
UID:10001303-1680516000-1680519600@cmsa.fas.harvard.edu
SUMMARY:Kähler-Einstein metrics on families of Fano varieties
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Chung-Ming Pan\, Institut de Mathématiques de Toulouse \nTitle: Kähler-Einstein metrics on families of Fano varieties \nAbstract: This talk aims to introduce a pluripotential approach to study uniform a priori estimates of Kähler-Einstein (KE) metrics on families of Fano varieties. I will first recall basic tools in the pluripotential theory and the variational approach to complex Monge-Ampère equations. I will then define a notion of convergence of quasi-plurisubharmonic functions in families of normal varieties and extend several classical properties under this context. Last\, I will explain how these elements help to obtain a purely analytic proof of the openness of existing singular KE metrics and a uniform $L^\infty$ estimate of KE potentials. This is joint work with Antonio Trusiani.
URL:https://cmsa.fas.harvard.edu/event/agst-4323/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-AGST-Seminar-04.03.2023.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230224T090000
DTEND;TZID=America/New_York:20230224T100000
DTSTAMP:20260501T213913
CREATED:20230825T085233Z
LAST-MODIFIED:20240228T100712Z
UID:10001302-1677229200-1677232800@cmsa.fas.harvard.edu
SUMMARY:On the convexity of general inverse $\sigma_k$ equations and some applications
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Chao-Ming Lin (University of California\, Irvine) \nTitle: On the convexity of general inverse $\sigma_k$ equations and some applications \nAbstract: In this talk\, I will show my recent work on general inverse $\sigma_k$ equations and the deformed Hermitian-Yang-Mills equation (hereinafter the dHYM equation). First\, I will show my recent results. This result states that if a level set of a general inverse $\sigma_k$ equation (after translation if needed) is contained in the positive orthant\, then this level set is convex. As an application\, this result justifies the convexity of the Monge-Ampère equation\, the J-equation\, the dHYM equation\, the special Lagrangian equation\, etc. Second\, I will introduce some semialgebraic sets and a special class of univariate polynomials and give a Positivstellensatz type result. These give a numerical criterion to verify whether the level set will be contained in the positive orthant. Last\, as an application\, I will prove one of the conjectures by Collins-Jacob-Yau when the dimension equals four. This conjecture states that under the supercritical phase assumption\, if there exists a C-subsolution to the dHYM equation\, then the dHYM equation is solvable.
URL:https://cmsa.fas.harvard.edu/event/agst-22423/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-02.24.2023.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221028T093000
DTEND;TZID=America/New_York:20221028T103000
DTSTAMP:20260501T213913
CREATED:20230825T084953Z
LAST-MODIFIED:20240215T092925Z
UID:10001301-1666949400-1666953000@cmsa.fas.harvard.edu
SUMMARY:2-Categories and the Massive 3d A-Model
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Ahsan Khan\, IAS \nTitle: 2-Categories and the Massive 3d A-Model \nAbstract: I will outline the construction of a 2-category associated to a hyperKahler moment map. The construction is based on partial differential equations in one\, two\, and three dimensions combined with a three-dimensional version of the Gaiotto-Moore-Witten web formalism. \n 
URL:https://cmsa.fas.harvard.edu/event/agst-102822/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-10.28.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221021T093000
DTEND;TZID=America/New_York:20221021T103000
DTSTAMP:20260501T213913
CREATED:20230825T081643Z
LAST-MODIFIED:20240215T093118Z
UID:10001300-1666344600-1666348200@cmsa.fas.harvard.edu
SUMMARY:The index of M-theory
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Nicolo Piazzalunga\, Rutgers \nTitle: The index of M-theory \nAbstract: I’ll introduce the higher-rank Donaldson-Thomas theory for toric Calabi-Yau threefolds\, within the setting of equivariant K-theory. I’ll present a factorization conjecture motivated by Physics. As a byproduct\, I’ll discuss some novel properties of equivariant volumes\, as well as their generalizations to the genus-zero Gromov-Witten theory of non-compact toric varieties.
URL:https://cmsa.fas.harvard.edu/event/agst-10212/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-10.21.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221014T093000
DTEND;TZID=America/New_York:20221014T103000
DTSTAMP:20260501T213913
CREATED:20230825T081331Z
LAST-MODIFIED:20240215T093308Z
UID:10001299-1665739800-1665743400@cmsa.fas.harvard.edu
SUMMARY:Singularities of the quantum connection on a Fano variety
DESCRIPTION:Algebraic Geometry in String Theory Seminar \n\n\n\n\n\nSpeaker: Daniel Pomerleano\, UMass Boston \nTitle: Singularities of the quantum connection on a Fano variety \nAbstract: The small quantum connection on a Fano variety is one of the simplest objects in enumerative geometry. Nevertheless\, it is the subject of far-reaching conjectures known as the Dubrovin/Gamma conjectures. Traditionally\, these conjectures are made for manifolds with semi-simple quantum cohomology or more generally for Fano manifolds whose quantum connection is of unramified exponential type at q=\infty. \nI will explain a program\, joint with Paul Seidel\, to show that this unramified exponential type property holds for all Fano manifolds M carrying a smooth anticanonical divisor D. The basic idea of our argument is to view these structures through the lens of a noncommutative Landau-Ginzburg model intrinsically attached to (M\, D).
URL:https://cmsa.fas.harvard.edu/event/agst-102122/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-10.14.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221007T093000
DTEND;TZID=America/New_York:20221007T103000
DTSTAMP:20260501T213913
CREATED:20230825T081109Z
LAST-MODIFIED:20240215T093620Z
UID:10001298-1665135000-1665138600@cmsa.fas.harvard.edu
SUMMARY:Scattering Diagrams from Holomorphic Discs in Log Calabi-Yau Surfaces
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Sam Bardwell-Evans\, Boston University\n\n\nTitle: Scattering Diagrams from Holomorphic Discs in Log Calabi-Yau Surfaces\n\nAbstract: In this talk\, we construct special Lagrangian fibrations for log Calabi-Yau surfaces and scattering diagrams from Lagrangian Floer theory of the fibers. These scattering diagrams recover the algebro-geometric scattering diagrams of Gross-Pandharipande-Siebert and Gross-Hacking-Keel. The argument relies on a holomorphic/tropical disc correspondence to control the behavior of holomorphic discs\, allowing us to relate open Gromov-Witten invariants to log Gromov-Witten invariants. This talk is based on joint work with Man-Wai Mandy Cheung\, Hansol Hong\, and Yu-Shen Lin.
URL:https://cmsa.fas.harvard.edu/event/agst/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-10.07.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220930T093000
DTEND;TZID=America/New_York:20220930T103000
DTSTAMP:20260501T213913
CREATED:20230825T080835Z
LAST-MODIFIED:20240215T093911Z
UID:10001297-1664530200-1664533800@cmsa.fas.harvard.edu
SUMMARY:GLSM\, Homological projective duality and nc resolutions
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker:  Mauricio Romo\, Tsinghua University \nTitle: GLSM\, Homological projective duality and nc resolutions\n\nAbstract: Kuznetsov’s Homological projective duality (HPD) in algebraic geometry is a powerful theorem that allows to extract information about semiorthogonal decompositions of derived categories of certain varieties. I will give a GLSMs perspective based on categories of B-branes. I will focus mostly on the case of Fano (hypersurfaces) manifolds. In general\, for such cases the HPD can be interpreted as a non-commutative (nc) resolution of a compact variety. I will give a physical interpretation of this fact and present some conjectures.
URL:https://cmsa.fas.harvard.edu/event/glsm-homological-projective-duality-and-nc-resolutions/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-09.30.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220426T093000
DTEND;TZID=America/New_York:20220426T103000
DTSTAMP:20260501T213913
CREATED:20230825T080553Z
LAST-MODIFIED:20240304T061555Z
UID:10001296-1650965400-1650969000@cmsa.fas.harvard.edu
SUMMARY:Modularity of mirror families of log Calabi–Yau surfaces
DESCRIPTION:Abstract:   In “Mirror symmetry for log Calabi–Yau surfaces I\,” given a smooth log Calabi–Yau surface pair (Y\,D)\, Gross–Hacking–Keel constructed its mirror family as the spectrum of an explicit algebra whose structure coefficients are determined by the enumerative geometry of (Y\,D). As a follow-up of the work of Gross–Hacking–Keel\, when (Y\,D) is positive\, we prove the modularity of the mirror family as the universal family of log Calabi-Yau surface pairs deformation equivalent to (Y\,D) with at worst du Val singularities. As a corollary\, we show that the ring of regular functions of a smooth affine log Calabi–Yau surface has a canonical basis of theta functions. The key step towards the proof of the main theorem is the application of the tropical construction of singular cycles and explicit formulas of period integrals given in the work of Helge–Siebert. This is joint work with Jonathan Lai.
URL:https://cmsa.fas.harvard.edu/event/modularity-of-mirror-families-of-log-calabi-yau-surfaces/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-04.26.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220419T093000
DTEND;TZID=America/New_York:20220419T103000
DTSTAMP:20260501T213913
CREATED:20230825T080357Z
LAST-MODIFIED:20240304T061057Z
UID:10001295-1650360600-1650364200@cmsa.fas.harvard.edu
SUMMARY:Equivariant Verlinde algebra and quantum K-theory of the moduli space of vortices
DESCRIPTION:Abstract:  In studying complex Chern-Simons theory on a Seifert manifold\, Gukov-Pei proposed an equivariant Verlinde formula\, a one-parameter deformation of the celebrated Verlinde formula. It computes\, among many things\, the graded dimension of the space of holomorphic sections of (powers of) a natural determinant line bundle over the Hitchin moduli space. Gukov-Pei conjectured that the equivariant Verlinde numbers are equal to the equivariant quantum K-invariants of a non-compact (Kahler) quotient space studied by Hanany-Tong. \nIn this talk\, I will explain the setup of this conjecture and its proof via wall-crossing of moduli spaces of (parabolic) Bradlow-Higgs triples. It is based on work in progress with Wei Gu and Du Pei.
URL:https://cmsa.fas.harvard.edu/event/equivariant-verlinde-algebra-and-quantum-k-theory-of-the-moduli-space-of-vortices/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-04.19.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220412T115800
DTEND;TZID=America/New_York:20220412T125800
DTSTAMP:20260501T213913
CREATED:20230825T080118Z
LAST-MODIFIED:20240304T061648Z
UID:10001294-1649764680-1649768280@cmsa.fas.harvard.edu
SUMMARY:Applications of Higher Determinant Map
DESCRIPTION:Abstract: In this talk I will explain the construction of a determinant map for Tate objects and two applications: (i) to construct central extensions of iterated loop groups and (ii) to produce a determinant theory on certain ind-schemes. For that I will introduce some aspects of the theory of Tate objects in a couple of contexts.
URL:https://cmsa.fas.harvard.edu/event/applications-of-higher-determinant-map/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220405T093000
DTEND;TZID=America/New_York:20220405T103000
DTSTAMP:20260501T213913
CREATED:20230825T075918Z
LAST-MODIFIED:20240304T082856Z
UID:10001293-1649151000-1649154600@cmsa.fas.harvard.edu
SUMMARY:Regularized integrals on Riemann surfaces and correlations functions in 2d chiral CFTs
DESCRIPTION:Abstract: I will report a recent approach of regularizing divergent integrals on configuration spaces of Riemann surfaces\, introduced by Si Li and myself in arXiv:2008.07503\, with an emphasis on genus one cases where modular forms arise naturally. I will then talk about some applications in studying correlation functions in 2d chiral CFTs\, holomorphic anomaly equations\, etc. If time permits\, I will also mention a more algebraic formulation of this notion of regularized integrals in terms of mixed Hodge structures. \nThe talk is partially based on joint works with Si Li.
URL:https://cmsa.fas.harvard.edu/event/regularized-integrals-on-riemann-surfaces-and-correlations-functions-in-2d-chiral-cfts/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-04.05.2022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220315T093000
DTEND;TZID=America/New_York:20220315T103000
DTSTAMP:20260501T213913
CREATED:20230825T075742Z
LAST-MODIFIED:20240304T082952Z
UID:10001292-1647336600-1647340200@cmsa.fas.harvard.edu
SUMMARY:2-categorical 3d mirror symmetry
DESCRIPTION:Abstract: It is by now well-known that mirror symmetry may be expressed as an equivalence between categories associated to dual Kahler manifolds. Following a proposal of Teleman\, we inaugurate a program to understand 3d mirror symmetry as an equivalence between 2-categories associated to dual holomorphic symplectic stacks. We consider here the abelian case\, where our theorem expresses the 2-category of spherical functors as a 2-category of coherent sheaves of categories. Applications include categorifications of hypertoric category O and of many related constructions in representation theory. This is joint work with Justin Hilburn and Aaron Mazel-Gee.
URL:https://cmsa.fas.harvard.edu/event/2-categorical-3d-mirror-symmetry/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220301T093000
DTEND;TZID=America/New_York:20220301T103000
DTSTAMP:20260501T213913
CREATED:20230825T075625Z
LAST-MODIFIED:20240304T083139Z
UID:10001291-1646127000-1646130600@cmsa.fas.harvard.edu
SUMMARY:Virtual localization for Artin stacks
DESCRIPTION:Abstract: This is a report about work in progress with: Adeel Khan\, Aloysha Latyntsev\, Hyeonjun Park and Charanya Ravi. We will describe a virtual Atiyah-Bott formula for Artin stacks.  In the Deligne-Mumford case our methods allow us to remove the global resolution hypothesis for the virtual normal bundle.
URL:https://cmsa.fas.harvard.edu/event/virtual-localization-for-artin-stacks/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-02.22.2022-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220222T093000
DTEND;TZID=America/New_York:20220222T103000
DTSTAMP:20260501T213913
CREATED:20230825T075425Z
LAST-MODIFIED:20240304T083230Z
UID:10001290-1645522200-1645525800@cmsa.fas.harvard.edu
SUMMARY:Higgs-Coulomb correspondence in abelian GLSM
DESCRIPTION:Abstract: We construct a certain type of Gauged Linear Sigma Model quasimap invariants that generalize the original ones and are easier to compute. Higgs-Coulomb correspondence provides identification of generating functions of our invariants with certain analytic functions that can be represented as generalized inverse Mellin transforms. Analytic continuation of these functions provides wall-crossing results for GLSM and generalizes Landau- Ginzburg/Calabi-Yau correspondence. The talk is based on a joint work in progress with Melissa Liu.
URL:https://cmsa.fas.harvard.edu/event/higgs-coulomb-correspondence-in-abelian-glsm/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-02.22.2022-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220215T093000
DTEND;TZID=America/New_York:20220215T103000
DTSTAMP:20260501T213913
CREATED:20230818T054001Z
LAST-MODIFIED:20240304T083319Z
UID:10001289-1644917400-1644921000@cmsa.fas.harvard.edu
SUMMARY:Virtual Coulomb branch and quantum K-theory
DESCRIPTION:Abstract: In this talk\, I will introduce a virtual variant of the quantized Coulomb branch constructed by Braverman-Finkelberg-Nakajima\, where the convolution product is modified by a virtual intersection. The resulting virtual Coulomb branch acts on the moduli space of quasimaps into the holomorphic symplectic quotient T^*N//G. When G is abelian\, over the torus fixed points\, this representation is a Verma module. The vertex function\, a K-theoretic enumerative invariant introduced by A. Okounkov\, can be expressed as a Whittaker function of the algebra. The construction also provides a description of the quantum q-difference module. As an application\, this gives a proof of the invariance of the quantum q-difference module under variation of GIT.
URL:https://cmsa.fas.harvard.edu/event/virtual-coulomb-branch-and-quantum-k-theory/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220208T093000
DTEND;TZID=America/New_York:20220208T103000
DTSTAMP:20260501T213913
CREATED:20230818T051427Z
LAST-MODIFIED:20240304T083416Z
UID:10001287-1644312600-1644316200@cmsa.fas.harvard.edu
SUMMARY:SYZ Conjecture beyond Mirror Symmetry
DESCRIPTION:Abstract: Strominger-Yau-Zaslow conjecture is one of the guiding principles in mirror symmetry\, which not only predicts the geometric structures of Calabi-Yau manifolds but also provides a recipe for mirror construction. Besides mirror symmetry\, the SYZ conjecture itself is the holy grail in geometrical analysis and closely related to the behavior of the Ricci-flat metrics. In this talk\, we will explain how SYZ fibrations on log Calabi-Yau surfaces detect the non-standard semi-flat metric which generalized the semi-flat metrics of Greene-Shapere-Vafa-Yau. Furthermore\, we will use the SYZ fibration on log Calabi-Yau surfaces to prove the Torelli theorem of gravitational instantons of type ALH^*. This is based on the joint works with T. Collins and A. Jacob.
URL:https://cmsa.fas.harvard.edu/event/syz-conjecture-beyond-mirror-symmetry/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20220201T093000
DTEND;TZID=America/New_York:20220201T103000
DTSTAMP:20260501T213913
CREATED:20230818T053619Z
LAST-MODIFIED:20240304T064710Z
UID:10001288-1643707800-1643711400@cmsa.fas.harvard.edu
SUMMARY:Curve-counting with fixed domain (“Tevelev degrees”)
DESCRIPTION:Abstract: We will consider the following problem: if (C\,x_1\,…\,x_n) is a fixed general pointed curve\, and X is a fixed target variety with general points y_1\,…\,y_n\, then how many maps f:C -> X in a given homology class are there\, such that f(x_i)=y_i? When considered virtually in Gromov-Witten theory\, the answer may be expressed in terms of the quantum cohomology of X\, leading to explicit formulas in some cases (Buch-Pandharipande). The geometric question is more subtle\, though in the presence of sufficient positivity\, it is expected that the virtual answers are enumerative. I will give an overview of recent progress on various aspects of this problem\, including joint work with Farkas\, Pandharipande\, and Cela\, as well as work of other authors.
URL:https://cmsa.fas.harvard.edu/event/curve-counting-with-fixed-domain-tevelev-degrees/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-02.01.2022-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20211207T093000
DTEND;TZID=America/New_York:20211207T103000
DTSTAMP:20260501T213913
CREATED:20230818T050741Z
LAST-MODIFIED:20240122T054102Z
UID:10001286-1638869400-1638873000@cmsa.fas.harvard.edu
SUMMARY:2d N=(0\,1) gauge theories\, Spin(7) orientifolds and triality
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/12-7-21-algebraic-geometry-in-string-theory/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20211130T093000
DTEND;TZID=America/New_York:20211130T103000
DTSTAMP:20260501T213913
CREATED:20230818T050118Z
LAST-MODIFIED:20240122T053703Z
UID:10001285-1638264600-1638268200@cmsa.fas.harvard.edu
SUMMARY:K_2 and Quantum Curves
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/k_2-and-quantum-curves/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20211116T093000
DTEND;TZID=America/New_York:20211116T103000
DTSTAMP:20260501T213913
CREATED:20240213T063545Z
LAST-MODIFIED:20240223T111731Z
UID:10002118-1637055000-1637058600@cmsa.fas.harvard.edu
SUMMARY:11/16/21 Algebraic Geometry in String Theory
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/11-16-21-algebraic-geometry-in-string-theory/
LOCATION:MA
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20211007T130000
DTEND;TZID=America/New_York:20211007T140000
DTSTAMP:20260501T213913
CREATED:20240214T053935Z
LAST-MODIFIED:20240304T063527Z
UID:10002541-1633611600-1633615200@cmsa.fas.harvard.edu
SUMMARY:A mirror theorem for GLSMs
DESCRIPTION:Abstract: A gauged linear sigma model (GLSM) consists roughly of a complex vector space V\, a group G acting on V\, a character \theta of G\, and a G-invariant function w on V.  This data defines a GIT quotient Y = [V //_\theta G] and a function on that quotient.  GLSMs arise naturally in a number of contexts\, for instance as the mirrors to Fano manifolds and as examples of noncommutative crepant resolutions. GLSMs provide a broad setting in which it is possible to define an enumerative curve counting theory\, simultaneously generalizing FJRW theory and the Gromov-Witten theory of hypersurfaces. Despite a significant effort to rigorously define the enumerative invariants of a GLSM\, very few computations of these invariants have been carried out.  In this talk I will describe a new method for computing generating functions of GLSM invariants.  I will explain how these generating functions arise as derivatives of generating functions of Gromov-Witten invariants of Y.
URL:https://cmsa.fas.harvard.edu/event/a-mirror-theorem-for-glsms/
LOCATION:MA
CATEGORIES:Algebraic Geometry in String Theory Seminar
END:VEVENT
END:VCALENDAR