Calendar

< 2022 >
March 27 - April 02
  • 27
    March 27, 2022
    No events
  • 28
    March 28, 2022
    No events
  • 29
    March 29, 2022

    CMSA General Relativity Program: The nonlinear stability of the Schwarzschild family of black holes

    All day
    March 29, 2022-April 1, 2022

    I will present aspects of a theorem, joint with Mihalis Dafermos, Gustav Holzegel and Igor Rodnianski, on the full finite codimension nonlinear asymptotic stability of the Schwarzschild family of black holes.

     

    March 29 – April 1, 2022: 10:00am – 12:00pm ET, each day

    Location: Hybrid. CMSA main seminar room, G-10. Zoom link will be available.

    All in-person attendees must register online.

    For more information, please see https://cmsa.fas.harvard.edu/gr-program/

     

    Math Picture Language Seminar: Matrix models, the enumeration of maps and free probability

    9:30 AM-10:30 AM
    March 29, 2022

    I will discuss the asymptotics of multimatrix models. In a small parameters (or high temperature) region, their free energy is well known to converge and to be related with the enumeration of maps. The latter can be proved by relating the so-called Dyson-Schwinger equations with Tutte surgery by nice pictures. In general, the convergence of the free energy is unknown, a problem which is closely related with the lack of a full entropy theory in free probability. We will discuss few models that can be analyzed, in particular in the large parameters (or low temperature) region.


    https://harvard.zoom.us/j/779283357?pwd=MitXVm1pYUlJVzZqT3lwV2pCT1ZUQT09

    How to count using equivariant cohomology?

    3:00 PM-4:00 PM
    March 29, 2022
    1 Oxford Street, Cambridge, MA 02138 USA

    How often does a general cubic surface appear in a 4-dimensional linear system?  As a slice of a general cubic 3-fold?  I will describe how we can solve problems of this kind using equivariant geometry.  This is joint work with Anand Patel and Dennis Tseng.


     

    Joint Harvard-CUHK-YMSC Differential Geometry Seminar: Elliptic chiral homology and chiral index

    9:30 PM-10:30 PM
    March 29, 2022

    We present an effective quantization theory for chiral deformation of two dimensional conformal field theories. We explain a connection between the quantum master equation and the chiral homology for vertex operator algebras. As an application, we construct correlation functions of the curved beta-gamma/b-c system and establish a coupled equation relating to chiral homology groups of chiral differential operators. This can be viewed as the vertex algebra analogue of the trace map in algebraic index theory. The talk is based on the recent work arXiv:2112.14572 [math.QA].


    Zoom link: https://cuhk.zoom.us/j/99612299554

    (Meeting ID: 996 1229 9554; Passcode: 20220330)

    Joint Harvard-CUHK-YMSC Differential Geometry Seminar: Elliptic chiral homology and chiral index

    9:30 PM-10:30 PM
    March 29, 2022

    We present an effective quantization theory for chiral deformation of two dimensional conformal field theories. We explain a connection between the quantum master equation and the chiral homology for vertex operator algebras. As an application, we construct correlation functions of the curved beta-gamma/b-c system and establish a coupled equation relating to chiral homology groups of chiral differential operators. This can be viewed as the vertex algebra analogue of the trace map in algebraic index theory. The talk is based on the recent work arXiv:2112.14572 [math.QA].


    For more information, please see: http://www.ims.cuhk.edu.hk/cgi-bin/SeminarAdmin/bin/Web

  • 30
    March 30, 2022

    CMSA General Relativity Program: The nonlinear stability of the Schwarzschild family of black holes

    All day
    March 30, 2022-April 1, 2022

    I will present aspects of a theorem, joint with Mihalis Dafermos, Gustav Holzegel and Igor Rodnianski, on the full finite codimension nonlinear asymptotic stability of the Schwarzschild family of black holes.

     

    March 29 – April 1, 2022: 10:00am – 12:00pm ET, each day

    Location: Hybrid. CMSA main seminar room, G-10. Zoom link will be available.

    All in-person attendees must register online.

    For more information, please see https://cmsa.fas.harvard.edu/gr-program/

     

    CMSA Colloquium: Edge Modes and Gravity

    9:30 AM-10:30 AM
    March 30, 2022

    In this talk I first review some of the many appearances of localized degrees of freedom — edge modes —  in a variety of physical systems. Edge modes are implicated for example in quantum entanglement and in various topological and holographic dualities. I then review recent work in which it has been realized that a careful treatment of such modes, paying attention to relevant symmetries, is required in order to properly understand such basic physical quantities as Noether charges. From many points of view, it is conjectured that this physics may be pointing at basic properties of quantum spacetimes and gravity.


    For information on how to join, please see:  https://cmsa.fas.harvard.edu/seminars-and-colloquium/

    CMSA Quantum Matter in Mathematics and Physics: Renormalization group flow as optimal transport

    10:30 AM-12:00 PM
    March 30, 2022

    We show that Polchinski’s equation for exact renormalization group flow is equivalent to the optimal transport gradient flow of a field-theoretic relative entropy.  This gives a surprising information-theoretic formulation of the exact renormalization group, expressed in the language of optimal transport.  We will provide reviews of both the exact renormalization group, as well as the theory of optimal transportation.  Our results allow us to establish a new, non-perturbative RG monotone, and also reformulate RG flow as a variational problem.  The latter enables new numerical techniques and allows us to establish a systematic connection between neural network methods and RG flows of conventional field theories.  Our techniques generalize to other RG flow equations beyond Polchinski’s.


    For information on how to join, please see:  https://cmsa.fas.harvard.edu/seminars-and-colloquium/

    CMSA New Technologies in Mathematics: Memorizing Transformer

    2:00 PM-3:00 PM
    March 30, 2022

    Language models typically need to be trained or fine-tuned in order to acquire new knowledge, which involves updating their weights. We instead envision language models that can simply read and memorize new data at inference time, thus acquiring new knowledge immediately. In this talk, I will discuss how we extend language models with the ability to memorize the internal representations of past inputs. We demonstrate that an approximate NN lookup into a non-differentiable memory of recent (key, value) pairs improves language modeling across various benchmarks and tasks, including generic webtext (C4), math papers (arXiv), books (PG-19), code (Github), as well as formal theorems (Isabelle). We show that the performance steadily improves when we increase the size of memory up to 262K tokens. We also find that the model is capable of making use of newly defined functions and theorems during test time.


    For information on how to join, please see:  https://cmsa.fas.harvard.edu/seminars-and-colloquium/

    The unbounded denominators conjecture

    3:00 PM-4:00 PM
    March 30, 2022
    1 Oxford Street, Cambridge, MA 02138 USA

    The unbounded denominators conjecture, first raised by Atkin and Swinnerton-Dyer, asserts that a modular form for a finite index subgroup of SL_2(Z) whose Fourier coefficients have bounded denominators must be a modular form for some congruence subgroup. In this talk, we will give a sketch of the proof of this conjecture based on a new arithmetic algebraization theorem. This is joint work with Frank Calegari and Vesselin Dimitrov.


     

  • 31
    March 31, 2022

    CMSA General Relativity Program: The nonlinear stability of the Schwarzschild family of black holes

    All day
    March 31, 2022-April 1, 2022

    I will present aspects of a theorem, joint with Mihalis Dafermos, Gustav Holzegel and Igor Rodnianski, on the full finite codimension nonlinear asymptotic stability of the Schwarzschild family of black holes.

     

    March 29 – April 1, 2022: 10:00am – 12:00pm ET, each day

    Location: Hybrid. CMSA main seminar room, G-10. Zoom link will be available.

    All in-person attendees must register online.

    For more information, please see https://cmsa.fas.harvard.edu/gr-program/

     

    CMSA Interdisciplinary Science Seminar: Compactification of an embedded vector space and its combinatorics

    9:00 AM-10:00 AM
    March 31, 2022

    Matroids are combinatorial abstractions of vector spaces embedded in a coordinate space.  Many fundamental questions have been open for these classical objects.  We highlight some recent progress that arise from the interaction between matroid theory and algebraic geometry.  Key objects involve compactifications of embedded vector spaces, and an exceptional Hirzebruch-Riemann-Roch isomorphism between the K-ring of vector bundles and the cohomology ring of stellahedral varieties.


    For information on how to join, please see:  https://cmsa.fas.harvard.edu/seminars-and-colloquium/

    Algebraic Dynamics Seminar: Eigenvalues of the Thurston Operator

    4:00 PM-6:00 PM
    March 31, 2022

    I will first explain the significance of Thurston’s pushforward operator for studying postcritically finite rational maps. I will then present some results due to Buff-Epstein-Koch which relate the eigenvalues of this operator to the multipliers of a rational map and also describe the set of eigenvalues of all unicritical polynomials of a given degree.


     

  • 01
    April 1, 2022

    CMSA General Relativity Program: The nonlinear stability of the Schwarzschild family of black holes

    All day
    April 1, 2022-April 1, 2022

    I will present aspects of a theorem, joint with Mihalis Dafermos, Gustav Holzegel and Igor Rodnianski, on the full finite codimension nonlinear asymptotic stability of the Schwarzschild family of black holes.

     

    March 29 – April 1, 2022: 10:00am – 12:00pm ET, each day

    Location: Hybrid. CMSA main seminar room, G-10. Zoom link will be available.

    All in-person attendees must register online.

    For more information, please see https://cmsa.fas.harvard.edu/gr-program/

     

    Special Talks by Harvard MATH Concentrators: Computational algebraic geometry and the Hilbert scheme

    10:00 AM-10:25 AM
    April 1, 2022
    1 Oxford Street, Cambridge, MA 02138 USA

    Raluca Vlad, will speak on Computational algebraic geometry and the Hilbert scheme


     

    Special Talks by Harvard MATH Concentrators: Lurie’s construction of Lubin-Tate spectra

    10:30 AM-10:55 AM
    April 1, 2022
    1 Oxford Street, Cambridge, MA 02138 USA

    Tristan Yang, will speak on Lurie’s construction of Lubin-Tate spectra


     

    Special Talk: (A)History of Shapes

    2:00 PM-2:45 PM
    April 1, 2022
    1 Oxford Street, Cambridge, MA 02138 USA

    Dylan Wilson will speak on (A)History of Shapes


     

    Special Talk: From unique factorization to the shapes of spaces

    3:15 PM-4:00 PM
    April 1, 2022
    1 Oxford Street, Cambridge, MA 02138 USA

    Melanie Wood will speak on From unique factorization to the shapes of spaces


     

  • 02
    April 2, 2022
    No events