Chennai Mathematical Institute
Seminars




Today's Seminar
  • 09-02-26
    Physics Seminar
    Date: Monday, 9 February 2026
    Time: 11.00 a.m. to 1.00 p.m.
    Venue: Lecture Hall 6
    The Geometrical Trinity of Gravity & Its Implications for Neutron Star Structure
    Sneha Pradhan
    BITS Pilani, Hyderabad.
    Abstract
    Recent advances in gravitational physics have renewed interest in the geometrical trinity of gravity, wherein General Relativity admits three equivalent formulations based on curvature (R), torsion (T), and non-metricity (Q). These alternative geometric descriptions provide deeper insights into the nature of gravity and provide promising frameworks for investigating strong-field astrophysical phenomena.

    This talk provides an overview of the geometrical trinity of gravity and its mathematical foundation in metric-affine geometry, with a particular focus on non-metricity-based f(Q) gravity. I will then discuss how the structure of neutron stars is constructed within the f(Q) framework and how departures from standard spacetime geometry can affect compact-star properties. I will show that modified gravity effects can enhance stellar compactness and allow stable neutron stars to populate the ob-servationally inferred mass-gap region. Finally, I will present recent work employing Bayesian inference, using NICER X-ray observations to statistically constrain f(Q) gravity parameters.


Today's Seminar
  • 09-02-26
    Seminar Announcement
    Date: Monday, 9 February 2026
    Time: 3.30 p.m. to 4.30 p.m.
    Venue: Lecture Hall 3
    Condorcets Paradox as Non-Orientability
    Ori Livson
    University of Sydney, Australia.
    Abstract
    Preference cycles arise naturally in collective decisionmaking and contradict transitive preference assumptions. This tension underlies Condorcets Paradox, which shows that reasonable axioms can force cyclic outcomes. While topology has enriched Social Choice Theory, explicit topological characterisations of preference cycles remain limited. We introduce a framework for modelling preference cycles topologically that generalises Baryshnikovs model of strict ordinal preferences on three alternatives. In this framework, Condorcets paradox corresponds to the nonorientability of a surface homeomorphic to the Klein bottle or the real projective plane, depending on the representation. This perspective allows Arrows Impossibility Theorem to be reformulated as a statement about surface orientability.


Forthcoming Seminars
  • 10-02-26
    Lecture Series on Social Choice Theory
    Lectures 1 and 2: Tuesday, 3 February 2026, from 10:30 a.m. to 1:05 p.m.
    Lectures 3 and 4: Tuesday, 10 February 2026, from 10:30 a.m. to 1:05 p.m.
    Venue: Lecture Hall 801
    Lecture Series on Social Choice Theory
    Ori Livson
    University of Sydney.

  • 20-02-26
    Seminar Announcement
    Date: Friday, 20 February 2026
    Time: 3.30 - 4.45 p.m.
    Venue: Seminar Hall
    Elliptic Characteristic Classes and Hecke Algebra
    Andrzej Weber
    Mathematical Institute, University of Warsaw.

  • 26-02-26
    Lecture Announcement
    Date Thursday, 26 February 2026
    Time: 3:30 p.m.
    Venue: Seminar Hall
    Scaling of multidimensional matrices and their applications
    T E S Raghavan
    Dept. of Math, Stat and computer Science, University of Illinois at Chicago.

Past Seminars (this year)
  • 04-02-26
    Physics Seminar
    Date: Wednesday, 4 February 2026
    Time: 2.00 to 3.00 p.m.
    Venue: Lecture Hall 4
    Bayesian inference of neutron star equations of state and analysis of stellar oscillations
    Debanjan Guha Roy
    BITS Pilani, Hyderabad Campus.

  • 03-02-26
    Seminar Announcement
    Date: Tuesday, 3 February 2026
    Time: 2.00 to 3:30 p.m.
    Venue: Lecture Hall 1
    Group Order and Group Non-Membership is in QCMA
    Dhara Thakkar
    Graduate School of Mathematics, Nagoya University.

  • 06-02-26
    Seminar Announcement
    Date: Friday, 06 February 2026
    Time: 3.30 p.m.
    Venue: Seminar Hall
    q-opers, QQ-systems and Bethe Ansatz for spin chains
    Rahul Singh
    YMSC, Tsinghua University.

  • 02-02-26
    Lecture Announcement
    Date: Monday, 2 February 2026
    Time: 2.00 p.m.
    Venue: Seminar Hall
    On Proper Descent of Smooth Affine Surfaces with Finite Homotopy Rank-Sum
    Buddhadev Hajra
    ISI Kolkata.

  • 02-02-26
    Physics Seminar
    Date: Monday, 2 February 2026
    Venue: Lecture Hall 6
    Time: 11.00 a.m. to 1.00 p.m
    String Compactifications And Cosmological Solutions, GKP Geometric Moduli
    Ratul Mahanta
    USTC, Hefei.

  • 30-01-26
    Physics Seminar
    Date: Friday, 30 January 2026
    Time: 11:45 a.m.
    Venue: Seminar Hall
    LIGO-India and the future of Gravitational Wave Astronomy
    Sanjit Mitra
    IUCAA, Pune.

  • 28-01-26
    Seminar Announcement
    Date: Wednesday, 28 January 2026
    Time: 3.30 to 4.30 p.m.
    Venue: Seminar Hall
    Some early Ramsey type theorems and some applications
    S. D. Adhikari
    RKMVERI.

  • 04-02-26
    Lecture series announcement
    Dates: 27, 28, 30 January and 2 & 4 February 2026
    Time: 3.45 to 4.45 PM
    Venue: NKN Hall (hybrid mode)
    Mock modularity of Calabi-Yau threefolds and BPS black holes
    Sergey Alexandrov
    Laboratoire Charles Coulomb and University of Montpellier, CNRS, France.

  • 03-02-26
    Lecture series announcement
    The dates of his lectures are:
    Lectures 1 and 2 will be on January 16 at 3:30 p.m. Both talks will be 45 minutes long, with a short break.
    Lectures 3 and 4 will be on January 27 and 29 from 3:30 p.m. to 4.30 p.m.
    Lectures 5 and 6 will be on February 2 and 3 from 3:30 p.m. to 4.30 p.m.
    Venue: Seminar Hall, CMI (hybrid mode)
    Actions of finite group schemes
    Michel Brion
    Institut Fourier at the UniversitE Grenoble Alpes, France.

  • 23-01-26
    Physics Seminar
    Date: Friday, 23 January 2026
    Time: 10.30 a.m. to 11.30 a.m.
    Venue: Lecture Hall 6
    Emergent Higher-Spin Symmetry on the Celestial Sphere from Loop-Corrected Soft Photon Theorems
    Biswajit Sahoo
    Kings College, London.

  • 22-01-26
    Physics Seminar
    Date: Thursday, 22 January 2026
    Venue: Lecture Hall 2
    Time: 1.30 p.m to 2.45 p.m.
    Modeling the gravitational-wave memory for coalescing compact binaries
    Marc Favata
    Montclair State University, USA.

  • 16-01-26
    Data Science Seminar
    Date: Friday, 16 January 2026
    Time: 2:00 p.m.
    Venue: NKN Hall
    Small Language Models: Design, Fine-Tuning and Deployment
    Sudhir Kumar
    Coriolis Technologies.

  • 16-01-26
    Seminar Announcement
    Date: Friday, 16 January 2026
    Time: 11.45 a.m.
    Venue: Seminar Hall
    Class groups of Kummer extensions associated to CM Elliptic curves
    Arindam Bhattacharya
    University of Massachusetts, Amherst.

  • 16-01-26
    Seminar Announcement
    Date: Friday, 16 January 2026
    Time: 11.45 a.m
    Venue: Lecture Hall 1
    A new characterization of VNP via Colored Determinant
    Prasad Chaugule
    IIT Delhi.

  • 13-01-26
    Seminar Announcement
    Date: Tuesday, 13 January 2026
    Time: 12:00 p.m
    Venue: Lecture Hall 4
    On the relative power of reduction notions in different characteristics
    Prasad Chaugule
    IIT Delhi.

  • 13-01-26
    Physics Seminar
    Date: Tuesday, 13 January 2026
    Time: 3:45 p.m.
    Venue: Lecture Hall 6
    Mock Modular forms and Vafa Witten Theory
    Aradhita Chattopadhyaya
    Chennai Mathematical Institute.

  • 12-01-26
    Physics Seminar
    Date: Monday, 12 January 2026
    Time: 3:45 p.m.
    Venue: Lecture Hall 6
    Mock Modular forms and Vafa Witten Theory
    Aradhita Chattopadhyaya
    Chennai Mathematical Institute.

  • 12-01-26
    Physics Seminar
    Date: Monday, 12 January 2026
    Time: 11.00 am to 1.00 p.m.
    Venue: Lecture Hall 6
    Boundary Energy-Momentum Tensors for Asymptotically Flat Spacetimes
    Vijay Nenmeli
    University of Edinburgh.

  • 09-01-26
    Computer Science Seminar
    Date: Friday, 9 January 2026
    Time: 2.00 - 3.15 p.m.
    Venue: Seminar Hall
    The complexity of the factors of polynomials
    Somnath Bhattacharjee
    University of Toronto.

  • 07-01-26
    Lecture Announcement
    Date: Wednesday, 7 January 2026
    Time: 4:00 p.m. - 4:30 p.m.
    Venue: Seminar Hall
    A Torelli type theorem for elliptic curves
    Tomasz Szemberg
    University of the National Education Commission, Krakow, Poland.

  • 07-01-26
    Lecture Announcement
    Date: Wednesday, 7 January 2026
    Time: 3:30 - 4:00 p.m.
    Venue: Seminar Hall
    Configurations of points in projective space and their projections
    Justyna Szpond
    University of the National Education Commission, Krakow, Poland.

  • 06-01-26
    Seminar Announcement
    Date: Tuesday, 6 January 2026
    Time: 2.00 to 3.30 p.m.
    Venue: Seminar Hall
    Redundancy is all you need (for CSP sparsification)
    Venkatesan Guruswami
    UC Berkeley and Simons Institute.

  • 05-01-26
    Seminar Announcement
    Date: Monday, 5 January 2026
    Time: 2.00 to 3.30 p.m.
    Venue: Seminar Hall
    Optimal Proximity Gaps for Subspace-Design Codes and (Random) Reed-Solomon Code\ s
    Rohan Goyal
    MIT.

  • 05-01-26
    Mathematics Seminar
    Date: Monday, 5 January 2026
    Time: 3.30 to 4.30 p.m.
    Venue: Seminar Hall
    The inverse system of Gorenstein points
    Maria Evelina Rossi
    University of Genoa.