Topology and Related Topics Seminar
Tuesday, 5 Sept 2023, 2:15 pm
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Venue: Ramanujan Hall
Host: Rekha Santhanam
Speaker: Priyanka Magar
Affiliation: IIT Bombay
Title: Quillen equivalent stable homotopy categories
Abstract: We will proceed by building upon the previous lectures, and explore different Quillen equivalent stable homotopy categories.
Seminar on Analysis of PDE
Tuesday, 05 September 2023, 03.45 pm
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Venue: Room 105, Department of Mathematics
Host: Harsha Hutridurga
Speaker: Subrata Majumdar
Affiliation: IIT Bombay
Title: Stabilization of heat equation by the backstepping method - I.
Abstract: This presentation considers the one-dimensional heat equation
with Dirichlet boundary conditions. We will study how we can make an
unstable (heat) system stable by means of some external input (control
function) through the boundary using the backstepping method. Our main
goal of this talk is to understand the backstepping method for the
simple 1-d heat case.
Algebraic Groups seminar
Tuesday, 5 September 2023, 4 pm
====================
Venue: Ramanujan Hall
Host: Shripad Garge
Speaker: Chayan Karmakar
Affiliation: IIT Bombay
Title: Differentials & Smooth Points - I
Abstract: We study differentials with the aim of introducing Lie algebras for algebraic groups.
Commutative Algebra Seminar
Tuesday. 5 September, 4 pm
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Venue: Room 215
Host: Tony Puthenpurakal
Speaker: Tony Puthenpurakal
Affiliation: IIT Bombay
Title: Triangulated and Derived Categories 4
Abstract: We continue our introduction to Triangulated categories
Lecture series on Hodge Theory
Wednesday and Thursday
6 and 7 September, 11:30 am – 1.00 pm
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Venue: Ramanujan Hall
Host: Sudarshan Gurjar
Speaker: V. Srinivas
Affiliation: IIT Bombay
Title: Introduction to Hodge Theory
Abstract: These are part of an ongoing series of lectures on the basics of Hodge theory. The next two lectures will finish the proof of the de Rham theorem, via sheaf cohomology, and if time permits, a beginning will be made on some linear algebra needed for the Hodge theory, as in Chapter 1 of Huybrechts' book.
CACAAG Seminar
Wednesday, 6 September, 5:30 PM
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Venue: Ramanujan Hall
Host: Madhusudan Manjunath
Speaker: Madhusudan Manjunath, IIT Bombay
Title: The Chow Ring of a Simplicial Toric Variety III.
Abstract: We will continue our study of the Chow ring of a simplicial toric variety.
Lecture series on Hodge Theory
Wednesday and Thursday
6 and 7 September, 11:30 am – 1.00 pm
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Venue: Ramanujan Hall
Host: Sudarshan Gurjar
Speaker: V. Srinivas
Affiliation: IIT Bombay
Title: Introduction to Hodge Theory
Abstract: These are part of an ongoing series of lectures on the basics of Hodge theory. The next two lectures will finish the proof of the de Rham theorem, via sheaf cohomology, and if time permits, a beginning will be made on some linear algebra needed for the Hodge theory, as in Chapter 1 of Huybrechts' book.
Topology and Related Topics Seminar
Thursday, 7 Sept 2023, 2:30 pm
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Venue: Room 215
Host: Rekha Santhanam
Speaker: Soumyadeb Samanta
Affiliation: IIT Bombay
Title: Some topological aspects of Riemannian geometry
Abstract: In this talk, I plan to prove the Cartan-Hadamard theorem which talks about the universal cover of a complete Riemannian manifold with non-positive sectional curvature. We shall also see a proof of Myer's theorem about the fundamental group of a complete Riemannian manifold with positive sectional curvature.
Lectures on algebraic stacks
Date and Time: Friday, 8th September at 11:30 am
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Venue: Ramanujan Hall
Host: Sudarshan Gurjar
Speaker: Nitin Nitsure
Affiliation: TIFR (retd)
Title: Algebraic Stacks
Abstract: Prof. Nitsure will continue his lectures on Algebraic Spaces.
Seminar on Analysis of PDE
Friday, 08 September 2023, 03.45 pm
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Venue: Room 105, Department of Mathematics
Host: Harsha Hutridurga
Speaker: Subrata Majumdar
Affiliation: IIT Bombay
Title: Stabilization of heat equation by the backstepping method - II.
Abstract: This presentation considers the one-dimensional heat equation
with Dirichlet boundary conditions. We will study how we can make an
unstable (heat) system stable by means of some external input (control
function) through the boundary using the backstepping method. Our main
goal of this talk is to understand the method of backstepping for the
simple 1-d heat case.
Topology and Related Topics Seminar
Tuesday, 12 September 2023, 2.30 -3:45 pm
=============================
Venue: Ramanujan Hall
Host: Rekha Santhanam
Speaker: Bittu Singh
Affiliation: IIT Bombay
Title: Quillen stratification theorem"
Abstract: In the 1st talk I'll describe group cohomology,
restrictions transfer, L-H-S and Quillen Venkov Lemma.
Seminar on Analysis of PDE
Tuesday, 12 September 2023, 04.00 pm
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Venue: Room 113, Department of Mathematics
Host: Harsha Hutridurga
Speaker: Bikram Bir
Affiliation: IIT Bombay
Title: A Splitting Discontinuous Galerkin Finite Element Method for the Vlasov-Navier-Stokes equation.
Abstract: In this talk, we shall discuss a splitting algorithm that we have developed to simulate
solutions to a two-phase flow model arising in the study of aerosols.
Algebraic Groups seminar
Tuesday, 12 September 2023, 4 pm
====================
Venue: Ramanujan Hall
Host: Shripad Garge
Speaker: Chayan Karmakar
Affiliation: IIT Bombay
Title: Differentials & smooth points - II
Abstract: We study differentials with the aim of introducing Lie algebras for algebraic groups.
Commutative Algebra Seminar
Tuesday. 5 September, 4 pm
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Venue: Room 215
Host: Tony Puthenpurakal
Speaker: Tony Puthenpurakal
Affiliation: IIT Bombay
Title: Triangulated and Derived Categories-VI
Abstract: We conclude our introduction to Triangulated categories.
Representation Theory seminar
Wednesday, 13 September 2023, 9:30 am
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Venue: Mini Conference Room
Host: U. K. Anandavardhanan
Speaker: Mohammed Saad Qadri
Affiliation: IIT Bombay
Title: On Higher Multiplicity upon Restriction from GL(n) to GL(n−1)
Abstract:
Let $F$ be a non-archimedean local field. Let $\Pi$ be a principal series representation of $\GL_n(F)$ induced from a cuspidal representation of a Levi subgroup. When $\pi$ is an essentially square integrable representation of $\GL_{n-1}(F)$ we prove that $\Hom_{\GL_{n-1}}(\Pi,\pi)$ $= \mathbb{C}$ and $\Ext^i_{\GL_{n-1}}(\Pi,\pi) = 0$ for all integers $i\geq 1$, with exactly one exception (up to twists), namely, when $\Pi= \nu^{-(\frac{n-1}{2})} \times \nu^{-(\frac{n-3}{2})} \times \ldots \times \nu^{(\frac{n-1}{2})}$ and $\pi$ is the Steinberg. When $\Pi= \nu^{-(\frac{n-1}{2})} \times \nu^{-(\frac{n-3}{2})} \times \ldots \times \nu^{(\frac{n-1}{2})}$ and $\pi$ is the Steinberg of $\GL_{n-1}(F)$, then $\dim \Hom_{\GL_{n-1}(F)}(\Pi,\pi)=n$. We also exhibit specific principal series for which each of the intermediate multiplicities $2, 3, \cdots, (n-1)$ are attained.
Along the way, we also give a complete list of those irreducible non-generic representations of $\GL_{n}(F)$ that have the Steinberg of $\GL_{n-1}(F)$ as a quotient upon restriction to $\GL_{n-1}(F)$. We also show that there do not exist non-generic irreducible representations of $\GL_{n}(F)$ that have the generalized Steinberg as a quotient upon restriction to $\GL_{n-1}(F)$.
Lecture series on Hodge Theory
Wednesday and Thursday
13 and 14 September, 11:30 am – 1.00 pm
---------------------------------------------
Venue: Ramanujan Hall
Host: Sudarshan Gurjar
Speaker: V. Srinivas
Affiliation: IIT Bombay
Title: Introduction to Hodge Theory
Abstract: These are part of an ongoing series of lectures on the basics of Hodge theory.
We will finish the proof of the de Rham theorem, via sheaf cohomology, and discuss some linear algebra needed for the Hodge theory, as in Chapter 1 of Huybrechts' book.
CACAAG seminar
Wednesday, 13 September, 5:30 PM
============================
Venue: Ramanujan Hall.
Host: Madhusudan Manjunath
Speaker: Madhusudan Manjunath, IIT Bombay
Title: The Chow Ring of a Simplicial Toric Variety IV.
Abstract: We will continue our study of the Chow ring of a simplicial toric variety.
Lecture series on Hodge Theory
Wednesday and Thursday
13 and 14 September, 11:30 am – 1.00 pm
---------------------------------------------
Venue: Ramanujan Hall
Host: Sudarshan Gurjar
Speaker: V. Srinivas
Affiliation: IIT Bombay
Title: Introduction to Hodge Theory
Abstract: These are part of an ongoing series of lectures on the basics of Hodge theory.
We will finish the proof of the de Rham theorem, via sheaf cohomology, and discuss some linear algebra needed for the Hodge theory, as in Chapter 1 of Huybrechts' book.
Lecture series on algebraic stacks
Friday, 15 September, 11:30 am
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Venue: Ramanujan Hall
Host: Sudarshan Gurjar
Speaker : Nitin Nitsure
Affiliation: TIFR, Mumbai (retd)
Title: Fibered groupoids and stacks.
Abstract: Schemes can be understood via their functors of points. Descent theory shows that these functors are big etale sheaves over Spec Z. Amongst such sheaves, schemes and algebraic spaces are characterized by further 'algebraicity' conditions. Similarly, algebraic stacks are fibered groupoids which are stacks, which are the analogue of the sheaf and descent conditions. A further 'algebraicity' condition defines algebraic stacks. In the next few lectures, we will look at fibered groupoids and stacks, and give many examples. This will prepare the ground for introducing the algebraicity conditions that characterize algebraic stacks.
Annual Progress Seminar
Wednesday ,
20 September 2023, 10:30 - 11:30 am
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Venue: Room 113
Host: Rekha Santhanam
Speaker: Bittu Singh
Affiliation: IIT Bombay
Title: Schwarz Genus of Fibration and Higher TC of Milnor Manifold
Abstract:
In my presentation, I will be discussing the Schwarz genus of fibration, with a particular focus on the intriguing genus known as Topological Complexity, which arises from free path space fibration. My research explores the Topological Complexity (TC) of several spaces. We finally obtained bounds for higher TC of Milnor manifolds. Our result also gives the higher TC of Klein Bottle
Annual Progress Seminar Tuesday, 26 September 2023, 10.30 - 11.30 am ============================== Venue: Room 113 Host: Ananthnarayan H. Speaker: Omkar Javadekar Affiliation: IIT Bombay Title: Associated Graded Modules and Pure Resolutions Abstract: Given a finitely generated module M over a Noetherian local ring R, one would like to know when the corresponding associated graded module G(M) has a pure resolution over the associated graded ring G(R). In this talk, we will construct a complex F* of free G(R)-modules using a minimal free resolution F of M over R, and show that F* is a minimal free resolution of G(M) if and only if G(M) is pure. We will apply this result to give sufficient conditions for R to be Cohen-Macaulay, and also prove a local version of Herzog-Kuhl equations.
Topology and Related Topics Seminar Tuesday, 26 Sept 2023, 2:30 pm ======================== Venue: Ramanujan Hall Host: Rekha Santhanam Speaker: Bittu Singh Affiliation: IIT Bombay Title: Quillen stratification theorem Abstract: This is the second talk. Here I will describe the topological aspect of group cohomology, the Equivalence of the algebraic and topological definitions. Then I will move to L-H-S and Quillen Venkov Lemma.
Annual Progress Seminar
Tuesday, September 26, 3 pm-4 pm
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Venue: Room-215
Host: Tony J. Puthenpurakal
Speaker: Sayed Sadiqul Islam
Title: Reductions of ideals in local rings
Abstract: The reduction theory goes back to the influential 1954 paper by Northcott and Rees, the paper that introduced the basic notions. We will prove the existence of minimal reductions and will discuss some properties of minimal reductions. A closely related notion is that of analytic spread l(I) of I is defined to be the Krull dimension of the fiber cone of I. We will see how analytic spread behaves in some special cases. If time permits then will introduce some new notions.
Algebraic Groups seminar Tuesday, 26 September 2023, 4 pm ============================= Venue: Ramanujan Hall Host: Shripad Garge Speaker: Chayan Karmakar Affiliation: IIT Bombay Title: Differentials & Smooth Points - III Abstract: We study smooth points on a variety and will try to introduce the notion of Lie algebra of a linear algebraic group.
Pre-Synopsis Seminar
Date: 27 September, 2023 (Wednesday),
Time: 11:00 AM to 12:00 noon
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Venue: Room 105
Host: Niranjan Balachandran
Speaker: Brahadeesh Sankarnarayanan
Title: Some problems in combinatorics: Excursions in graph colorings and
extremal set theory
All are cordially invited.
Lecture series on Hodge Theory Wednesday 27 September, 11:30 am and 3.30 pm ---------------------------------------------------- Venue: Ramanujan Hall at 11.30 and 215 at 3.30 Host: Sudarshan Gurjar Speaker: V. Srinivas Affiliation: IIT Bombay Title: Introduction to Hodge Theory Abstract : These are part of an ongoing series of lectures on the basics of Hodge theory. We will finish the proof of the de Rham theorem, via sheaf cohomology, and discuss some linear algebra needed for the Hodge theory, as in Chapter 1 of Huybrechts' book.
Annual Progress Seminar Wednesday, 27th September 2023, 12 noon ======================================= Venue: Room 105 Host: Debraj Das Speaker: Ms. Janhvi Patel Affiliation: IIT Bombay Title: High-Dimensional Berry Essen Bounds for M-estimators Abstract: M-estimation refers to a general method of estimation methods, where the estimators are obtained by maximizing certain criterion functions. M-estimators include the maximum likelihood estimator, lease square estimator, and many other estimators that appear in robust regression. Here we are interested in high dimensional asymptotics of M-estimators. More precisely, our goal is to find the Berry-Essen bound on the difference between the law of properly centered and scaled M estimator and an appropriate Gaussian distribution.
Annual Progress Seminar Wednesday, 27th September 2023, 3.00 pm ===================================== Venue: Ramanujan Hall Host: Debraj Das Speaker: Mr. Mayukh Choudhury Affiliation: IIT Bombay Title: Bootstrapping LASSO in Generalized Linear Models Abstract: Generalized linear models or GLM is an important set of models that generalizes the ordinary linear regression by connecting the response variable with the covariates through arbitrary link functions and thus allowing the responses to have arbitrary distributions. On the other hand, the Least Absolute Shrinkage and Selection Operator or the Lasso is a popular and easy-to-implement penalization method in regression especially when all the covariates are not relevant. However, Lasso has complicated asymptotic distribution which is not useful in practice and hence development of an alternative method of distributional approximation is required for the purpose of statistical inference. Bootstrap generally works as an alternative in most of the inference problems. In that spirit, here we develop a Bootstrap method that works as an approximation of the distribution of the Lasso estimator for all the sub-models of GLM. However, it is the usual practice that cross-validation is used to choose a data-dependent choice of the penalty parameter in Lasso. To bridge the gap between the developed Bootstrap theory and the use of cross-validation, we also establish the asymptotic property of the K-fold cross-validated choice of the penalty parameter.
Lecture series on Hodge Theory Wednesday 27 September, 11:30 am and 3.30 pm ---------------------------------------------------- Venue: Ramanujan Hall at 11.30 and 215 at 3.30 Host: Sudarshan Gurjar Speaker: V. Srinivas Affiliation: IIT Bombay Title: Introduction to Hodge Theory Abstract : These are part of an ongoing series of lectures on the basics of Hodge theory. We will finish the proof of the de Rham theorem, via sheaf cohomology, and discuss some linear algebra needed for the Hodge theory, as in Chapter 1 of Huybrechts' book.
Annual Progress Seminar Friday, 29 September 2023, 11.05 am ======================= Venue: Ramanujan Hall Host: Prof. Sudhir Ghorpade Speaker: Rati Ludhani Affiliation: IIT Bombay Title: Projective Reed-Muller Codes and Minimal Free Resolutions
Annual Progress Seminar Friday, 29 September 2023, 12.05 pm =========================== Venue: Ramanujan Hall Host: Prof. Sudhir Ghorpade Speaker: Sakshi Affiliation: IIT Bombay Title: Minimum Weight Codewords and Permutation Automorphism Groups of Affine Cartesian Codes
Annual Progress Seminar
Wednesday, 27 September, 2.00-3.00 pm
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Venue: Ramanujan Hall
Host: Prof. Niranjan Balachandran
Speaker: Ankita Dargad, IIT Bombay
Title: Robin Hood Game
Topology and Related Topics Seminar Friday, 29 Sept 2023, 2:30 pm ======================== Venue: Ramanujan Hall Host: Rekha Santhanam Speaker: Aparajita Karmakar Affiliation: ISI Kolkata Title: Homotopy invariant commutative algebra Abstract: The goal of this lecture will be to introduce the concept of Morita equivalences. In Morita theory, we study an object X of a category by considering Hom(k,X) as a module over the endomorphism ring End(k), where k is a test object. Towards that, we will develop some finiteness conditions on an R - complex, where R is a commutative local ring, and their applications in Morita Theorems.
Annual Progress Seminar
Friday, 29 September 2023, 4.00 pm
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Venue: Ramanujan Hall
Host: Prof. Siuli Mukhopadhyay
Speaker: Pallab Kumar Sinha
Affiliation: IIT Bombay
Annual Progress Seminar
Friday, 29 September 2023, 4.45 pm
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Venue: Ramanujan Hall
Host: Prof. Siuli Mukhopadhyay
Speaker: Niphadkar Shubham Sanjay
Affiliation: IIT Bombay
Title: Efficient Bivariate Crossover Designs in Correlated Setup