MS Talk Series

‘How is it to do an MS thesis?’, ‘What does writing a paper feel like?’, ‘What are the topics and exciting areas of research out there?’ These questions are always there in the minds of BS-MS students. This will be a series of talks intended to give the general audience an appreciation for the work carried out during the MS thesis. 5th-year Mathematics BS-MS students who are going to present their MS thesis work this year are going to deliver these talks.

LHC 101

3rd-16th April 2023 , 07:00pm

Talks of 2023

Loop Groups and Simplicial Homotopy Theory  - Karthik Vasisht

Abstract: In this talk, we introduce simplicial homotopy theory and its relation to "classical"  algebraic topology. The talk will begin with the basic notions of homotopy and homotopy  groups from algebraic topology. We then introduce the notion of simplicial sets and the  simplicial versions of homotopy and homotopy groups. Finally, we'll look at a situation  where working with simplicial sets is more advantageous as compared to working with  topological spaces. The talk will involve many examples to make it easier to understand the  concepts that are being developed. I will also talk about my experiences in conducting  research for the past year.  

Date & Time:  3rd April 2023, 07:00pm

The 'Lonely Runner Conjecture' - Hrishikesh V

Abstract: Imagine that you are running on a circular track. For company, you have a few  friends with you. No two of you run at the same speed and all of you  have a constant, non-zero speed. If you all run in the same direction, will there ever be a  moment when you are a set minimum distance apart from the friend nearest to you? Does the  same thing happen with each of your friends?  In this talk, we shall look at different formulations of the conjecture, and the various  approaches that have been taken to tackle the problem. I’ll then explain,  in brief, how the conjecture can be viewed geometrically using the concept of polyhedra.  Finally, we see some of the important known results, especially those proven using the  polyhedral theory approach.  

Date & Time : 4th April 2023, 07:00pm

How large can homogeneous sets in Graphs be?   - Mihir Neve

Abstract: Consider the party problem - Given 6 people at a party, you can always find 3  people who are all either mutually friends or mutually strangers. Such symmetric relations are  best captured in math by the notion of 'Graphs' - a set of nodes, where two nodes are joined  by an edge if they are related in some way. No, these aren't the same graphs which we usually  see in our calculus courses, but are interesting nevertheless.   In a graph, if a subset of nodes are all pairwise connected or pairwise disconnected, like the 3  people above, then it is said to be a homogeneous set. We ask the question: "Given a graph,  how large homogeneous sets can it have?"   In this talk, we shall look at some basics of graphs, and take a dive into the world of Ramsey  Theory and Structural Graph Theory while trying to answer this question. We shall look at  the Erdös-Hajnal conjecture, and as we shall see, help comes from a surprising place.  

Date & Time: 5th April 2023, 07:00pm

Characterization of Uniform Pro-p Groups - A P Aravintakshan  

Abstract: Profinite Groups are a fascinating family of topological groups which can be also  defined using the notion of an inverse limit. We start by discuss this equivalence, and using  this theory we try to understand various different kinds of profinite groups such as Pro-p  Groups, Powerful Pro-p Groups, and Uniform Pro-p Groups. Uniform Pro-p Groups have a  well-defined structure to them being torsion free and homoeomorphic to 𝐙pd, where d is the  number of topological generators of the group, and has far reaching applications in the field  of Number Theory. We then elaborate on the characteristics of various different families of  Uniform Pro-p Groups.  

Date & Time: 10th April 2023, 07:00pm

A tour of graph transformation problems  - Anirudh Rachuri  

Abstract: Consider two clusters of computers, that have constant communication with  each other. Due to an increase in malware in one of the clusters, you want to cut  off communication between the two. However, these computers are performing vital tasks,  and you can only switch off a limited number of them. How do you decide which computers  to switch off?  The field of graph theory is filled with a plethora of such algorithmic problems. Many of  these are deemed “too hard to solve”, however, there exist numerous ways to get around this  issue. One of the more popular ways is to only allow inputs satisfying a certain property. By  restricting our inputs, we can exploit their properties, and perhaps come up with efficient  solutions for the problem at hand. In this talk, I will focus on one of the most prevalent and  well-studied graph class, namely the class of chordal graphs. We will explore some of its  beautiful properties, and understand how one can use them to build efficient algorithms.  

Date & Time: 11th April 2023, 07:00pm

Simplicial Complexes on Seifert Surfaces of Knots - A Tale of Two Structures - Ipsa Bezbarua    

Abstract: Over the last century, knot theory has developed into an active area of research in  topology. This is partly due to its connections with several other areas of science and  technology. In the domain of mathematics, low-dimensional topologists look to results and  techniques from knot theory to gain a better understanding of 3-manifolds. One of the  fundamental structures studied in knot theory is a compact connected surface whose  boundary is the knot under consideration, called a Seifert surface. In this talk, we will learn  various properties related to two well-known simplicial complexes constructed using the  Seifert surfaces of knots - the incompressible complex and the Kakimizu complex (named  after Osamu Kakimizu). We will look at some classic properties of the Kakimizu complex,  the more popular of the two, like contractibility and local infiniteness. I will then talk about  my experiences of trying to extend some of these properties to the seemingly less cool  incompressible complex, who (SPOILER ALERT) may be a lot more interesting than we  originally thought. I will also recount my experiences of reasoning with (aka, researching)  these complexes.

Date & Time: 12th April 2023, 07:00pm

Exact Exponential Algorithms - Ajaykrishnan ES  

Abstract: Imagine yourself to be a tiny fish frantically looking for directions to” P.Sherman,  42 Wallaby Way, Sydney”. Since time is of the essence, you and your friend collects various  pieces of information which might help find the way. Unfortunately, many of them end up  contradicting each other and you are left with no choice but to ignore a few. In the talk we  shall see how hopeless our situation can be, but considering how crucial our task is, we will  do the best we can to solve the problem. Along the way, we shall learn what P and NP are  and why a lot of people believe them to not be equal. We will observe that this conjecture (if  true) leaves us with a lot of problems that cannot be solved efficiently and explore a way to  cope with this intractability.  In the end, we could also briefly look at another problem called Knot-Free Vertex Deletion  which is central to my Masters thesis and go over some ideas which were helpful in designing  a faster algorithm for the same.  

Date & Time: 13th April 2023, 07:00pm

Computational Complexity of the Pilot Assignment problem in Cell-Free Massive  MIMO - Shruthi Prusty  

Abstract: Wireless networks is an essential technology for enabling flexible communication  and connectivity between individuals (or machines) across regions. In addition, it is  transforming every sector of the economy (transportation, healthcare, education, etc.), and  powerful new technologies (artificial intelligence, internet of things, etc.) are being built upon  it. Cellular networks is the technology that 1G to 5G relies on. However, as the number of  devices that depend on wireless communication networks continues to grow, each needing a  high connection rate and better coverage with minimal interference, this technology will no  longer be suitable. For future wireless communications (e.g., 6G), the key technology that has  the potential to enhance connectivity and provide better coverage for billions of users is  referred to as Cell-Free Massive Multiple-Input Multiple-Output (CF-mMIMO).    CF-mMIMO is accompanied by many challenges, one of which is how to efficiently manage  limited resources, giving rise to the resource allocation problem in wireless networks. This  talk will describe a major problem that hinders resource allocation in wireless networks,  namely the Pilot Assignment problem (PA). To design heuristics that can find reasonably  good solutions to PA, the problem has been mapped to several well-known graph theory  problems which fall in the class of NP-hard problems. However, there is no literature that  formally states the PA problem as a mathematical problem, let alone explicitly prove  complexity results for it. The aim of this talk is to look at the pilot assignment problem from  a theoretical computer science perspective and present a few results on the complexity and  approximability of this problem. We discuss our findings in the context of the algorithms  already proposed in the literature to tackle this problem. 

Date & Time: 14th April 2023, 07:00pm

Formalising mathematics and algorithms using computers   - Anand Tadipatri  

Abstract: Proof assistants are softwares capable of verifying mathematical arguments down to  their foundational details. Those built on the mathematical foundation of type theory can also  be used as programming languages, due to a deep correspondence between programs and  proofs. The first half of this talk will introduce proof assistants and their various capabilities,  with a particular focus on the Lean4 proof assistant.   In the second half, I will speak about a recent formalisation work done jointly with my MS  advisor Dr. Siddhartha Gadgil, which illustrates how a proof assistant may be used to  formalise results that involve both proofs and computations.   The talk will conclude with a demonstration of a tool for automatically formalising  mathematical statements to Lean code.     

Date & Time: 15th April 2023, 07:00pm

The geometry of curves and the shapes of minimal surfaces joining them - Sreedev M   

Abstract: Minimal surfaces are zero mean curvature surfaces that appear in nature as  idealized soap films. Given two curves one can ask for a minimal surface connecting them. In  this talk, we would look at the shapes of such curves and how it controls the image of the  minimal surfaces interpolating them. Besides containing lots of creative arguments involving  beautiful pictures, this talk would also explore various other different branches such as  Fourier analysis, complex analysis, split-complex analysis, functional analysis, and so on.  This is a joint work with Prof. Rukmini Dey (ICTS Bangalore).  

Date & Time: 16th April 2023, 07:00pm