• CMSA EVENT: Algebraic Geometry in String Theory Seminar: Motivic decomposition of moduli space from brane dynamics

    Speaker: Kai Xu – CMSA

    10:00 AM-11:30 AM
    October 2, 2023
    20 Garden Street, Cambridge, MA 02138

    Supersymmetric gauge theories encode deep structures in algebraic geometry, and geometric engineering gives a powerful way to understand the underlying structures by string/M theory. In this talk we will see how the dynamics of M5 branes tell us about the motivic and semiorthogonal decompositions of moduli of bundles on curves.


    Please note that there will be a pre-talk by Kai Xu from 10:00 am before the main talk at 10:30

  • OTHER MATHEMATICS DEPARTMENT EVENTS: Jameel Al-Aidroos Mathematical Pedagogy Lecture Series

    Jameel Al-Aidroos Mathematical Pedagogy Lecture Series

    Speaker: Gregory R. Goldsmith – Schmid College of Science and Technology at Chapman University

    3:00 PM-4:30 PM
    October 2, 2023

    Join us for the second annual Jameel Al-Aidroos Mathematical Pedagogy Lecture Series

    When: October 2, 2023 | 3 p.m. – 4:30 p.m.

    Where: Science Center Room 507, 1 Oxford Street, Cambridge, MA, 02138

    Speaker: Gregory R. Goldsmith

    • What does it mean to mentor?
    • Every mentor is different. Every mentee is different.

    Greg Goldsmith is the Associate Dean for Research and Development and an Associate Professor of Biological Sciences in the Schmid College of Science and Technology at Chapman University. He served for six years as the first director of the Grand Challenges Initiative, building it into one of the nation’s largest and most comprehensive postdoctoral training programs.


    This speaker series is a small way to remember Jameel Al-Aidroos, his extraordinary warmth of character and pedagogical skills, and his contributions and dedication to teaching and learning at Harvard. He motivated and inspired his students and colleagues; through this series, we hope to celebrate and keep alive that legacy by bringing speakers who share new perspectives on mathematics and pedagogy, and motivate us to reflect on our professional roles.


    • Robin Gottlieb | Harvard Professor of the Practice in Teaching of Mathematics
    • Brendan Kelly | Harvard Department of Mathematics Senior Preceptor, Director of Introductory Mathematics
  • CMSA EVENT: CMSA Colloquium: Gravitational Instantons

    Speaker: Yu-Shen Lin – Boston University

    4:30 PM-5:30 PM
    October 2, 2023
    20 Garden Street, Cambridge, MA 02138

    Gravitational instantons were introduced by Hawking as building blocks of his Euclidean quantum gravity theory back in the 1970s. These are non-compact Calabi-Yau surfaces with L2 curvature and thus can be viewed as the non-compact analogue of K3 surfaces. K3 surfaces are 2-dimensional Calabi-Yau manifolds and are usually the testing stone before conquering the general Calabi-Yau problems. The moduli space of K3 surfaces and its compactification on their own form important problems in various branches in geometry. In this talk, we will discuss the Torelli theorem of gravitational instantons, how the cohomological invariants of a gravitational instanton determine them. As a consequence, this leads to a description of the moduli space of gravitational instantons.


  • HARVARD-MIT ALGEBRAIC GEOMETRY SEMINAR: Harvard-MIT Algebraic Geometry Seminar: The Minimal Exponent of LCI Subvarieties

    Speaker: Brad Dirks – Stony Brook

    3:00 PM-4:00 PM
    October 3, 2023
    1 Oxford Street, Cambridge, MA 02138 USA

    Classification of singularities is an interesting problem in many areas of algebraic geometry, like the minimal model program. One classical approach is to assign to a variety a rational number, its log canonical threshold. For complex hypersurface singularities, this invariant has been refined by M. Saito to the minimal exponent. This invariant is related to Bernstein-Sato polynomials, Hodge ideals and higher du Bois and higher rational singularities.

    In joint work with Qianyu Chen, Mircea Mustață and Sebastián Olano, we defined the minimal exponent for LCI subvarieties of smooth complex varieties. We relate it to local cohomology, higher du Bois and higher rational singularities. I will describe what was done in the hypersurface case, give our definition in the LCI case and explain the relation to local cohomology modules and the classification of singularities.


    Harvard-MIT Algebraic Geometry Seminar: TBA

    Speaker: Alex Pieloch – MIT

    3:00 PM-4:00 PM
    October 10, 2023

    Abstract TBA

    Please note MIT location

    For more information, please see

  • CMSA EVENT: CMSA Topological Quantum Matter Seminar: Chern Mosaic and ideal bands in helical trilayer graphene

    Speaker: Daniele Guerci – Flatiron Institute

    4:00 PM-5:00 PM
    October 10, 2023
    20 Garden Street, Cambridge, MA 02138
    In this talk I will present helical trilayer graphene (hTTG) which is characterized an emergent real-space Chern mosaic pattern resulting from the interface of two incommensurate moiré lattices [1]. This pattern shows distinct regions with finite integer Chern numbers separated by domain walls where the spectrum is gapless and connected at all energy scales [2]. After introducing the Hamiltonian describing hTTG I will focus my attention on the macroscopic domains, that host isolated flat bands with intriguing properties. Upon investigating the chiral limit, where analytical expressions can be derived, we found that the flat bands features the superposition of a Chern -1 and a Chern 2 bands described by the superposition of two lowest Landau level [2,3]. The origin of the flat bands can be explained using a combination of geometrical relations and symmetry arguments [3]. Building on this knowledge, I will discuss the properties of the zero-modes at higher magic angles.
    [1] Y.Mao,D.Guerci,C.Mora, PRB 107, 125423 (2023) [Editors’ Suggestion]
    [2] D.Guerci,Y.Mao,C.Mora, arXiv:2305.03702 (2023)
    [3] D.Guerci,Y.Mao,C.Mora, arXiv:2308.02638 (2023)

    This seminar will be held in person and on Zoom:

    Password: 353114

  • CMSA EVENT: Algebraic Geometry in String Theory Seminar: Moduli of boundary polarized Calabi-Yau pairs

    Speaker: Dori Bejleri – CMSA

    10:00 AM-11:30 AM
    October 16, 2023
    20 Garden Street, Cambridge, MA 02138

    The theories of KSBA stability and K-stability furnish compact moduli spaces of general type pairs and Fano pairs respectively. However, much less is known about the moduli theory of Calabi-Yau pairs. In this talk I will present an approach to constructing a moduli space of Calabi-Yau pairs which should interpolate between KSBA and K-stable moduli via wall-crossing. I will explain how this approach can be used to construct projective moduli spaces of plane curve pairs. This is based on joint work with K. Ascher, H. Blum, K. DeVleming, G. Inchiostro, Y. Liu, X. Wang.

    Please note that there will be a pretalk by Rosie Shen (Harvard Math) from 10:00 am before the main talk at 10:30. The title of this pretalk is “Introduction to the singularities of the MMP.”

  • CMSA EVENT: CMSA Colloquium: An exploration of infinite games—infinite Wordle and the Mastermind numbers

    Speaker: Joel D. Hamkins – Notre Dame and Oxford

    4:30 PM-5:30 PM
    October 16, 2023
    20 Garden Street, Cambridge, MA 02138
    Let us explore the nature of strategic reasoning in infinite games, focusing on the cases of infinite Wordle and infinite Mastermind. The familiar game of Wordle extends naturally to longer words or even infinite words in an idealized language, and Mastermind similarly has natural infinitary analogues. What is the nature of play in these infinite games? Can the codebreaker play so as to win always at a finite stage of play? The analysis emerges gradually, and in the talk I shall begin slowly with some easy elementary observations. By the end, however, we shall engage with sophisticated ideas in descriptive set theory, a kind of infinitary information theory. Some assertions about the minimal size of winning sets of guesses, for example, turn out to be independent of the Zermelo-Fraenkel ZFC axioms of set theory. Some questions remain open.