University of Illinois, USA
Title: RAMANUJAN: MORE THAN A CENTURY OF INSPIRATION
Abstract: We begin with an account of Ramanujan’s life. Histories of Ramanujan’s (earlier) notebooks and lost notebook will be given. I will then describe my involvement with Ramanujan’s notebooks and lost notebook during the past 47 years. The lecture will conclude with some examples taken from Ramanujan’s notebooks and his lost notebook. Most of the lecture will be accessible to a general audience.
The Pennsylvania State University, USA
Title: Ramanujan's Lost Notebook in Five Volumes __ Afterthoughts
Abstract: Ramanujan composed two Notebooks of his discoveries prior to coming to Cambridge in1914. Upon his return to India in 1919, he filled another 100 plus pages with formulas discovered during this last year of his life. The latter is referred to as his Lost Notebook; it lay unexamined until 1976. Bruce Berndt devoted 5 volumes (published by Springer) to the mathematics contained in the original two Notebooks. Bruce Berndt and I published five volumes giving proofs of these results in the Lost Notebook. The fifth volume appeared in 2018
It is important to note a couple of things concerning the Lost Notebook. First, through the efforts of many currently active researchers, every formula in the Notebooks has now been proved (or in a minimally few cases, disproved). However, there are many results that have great importance currently (e.g. assertions about the mock theta functions) where it is almost certain that the modern proofs are radically different from Ramanujan's understanding of the results. To put it another way, there are many results in the Lost Notebook (especially those dealing with the mock theta functions) which seem impossible to discover (even by Ramanujan) without some overarching theory. Furthermore, the modern proofs contain intermediate results which, owing to their elegance and simplicity, Ramanujan certainly would have included in the Lost Notebook had he known them. All this leads to the very natural conclusion that Ramanujan knew many things and had many methods that are currently unknown to us. The object of this talk will be to draw attention to aspects of the Lost Notebook where Ramanujan's discoveries have left mysteries that are well worth exploring. It is hoped that this will point to and encourage further investigation.
The Institute of Mathematical Sciences, India
Title: Saturation for refined Littlewood-Richardson Coefficients
Abstract: Littlewood-Richardson (LR) coefficients are arguably the most celebrated numbers in all of algebraic combinatorics. They are, by definition, the multiplicative structure constants of the ring of symmetric polynomials (in a fixed number n of variables) with respect to the basis of Schur polynomials (which are parametrized by partitions with at most n parts). They have representation theoretic (and geometric) significance: they encode how the tensor product of two irreducible polynomial representations of the general linear group GL(n) decomposes as a direct sum of irreducible representations. Considering a certain natural class of submodules of the tensor product, called the Kostant-Kumar modules, we are led to the notion of refined LR coefficients. We prove a saturation theorem for the refined LR coefficients generalising the well known result, conjectured by Klaychko and proved by Knutson-Tao, for the usual LR coefficients. This talk is based on joint work with Mrigendra Singh Kushwaha and Sankaran Viswanath.
Notwithstanding the technical terms in the above paragraph, an attempt will be made to make the talk accessible to a general audience.
Massey University, Auckland, New Zealand
Title: The Rogers—Ramanujan continued fraction
Abstract: Just over 100 years ago, an unknown clerk from India wrote some letters to Cambridge mathematician G. H. Hardy. About certain results in one of the letters, Hardy later wrote
“(they) defeated me completely; I had never seen anything in the least like them before”
and concluded
"A single look at them is enough to show that they could only be written down by a mathematician of the highest class.”
I will describe these particular results, put them in a modern context, and outline some recent developments.
Université d'Évry Val d'Essonne, France
Title: Multiplicative partitions and Zeta functions
Abstract: In this talk, we investigate an important family of multiplicative partition functions. For these partition functions, we treat their arithmetic properties. Among others, for these functions we give
• Explicit formula and algorithm for computation;
• Average and error term;
• Upper and lower bounds;
• Estimate of Champions numbers and large values.
The main tool is the study of their associated zeta generating functions.
National Institute of Technology Karnataka, India
Title: Problems in Additive Number Theory
Abstract:
Tezpur University, Assam, India
Title: Matching coefficients in the series expansions of certain q-products and their reciprocals
Abstract:
University of Mysore, Mysuru, Karnataka, India
Title: On Gosper’s Πq and Lambert series identities
Abstract: In an interesting article entitled “Experiments and discoveries in q - trigonometry”, R. W. Gosper defined a constant Πq, which is in fact Ramanujan’s theta function ψ(q). In the same article, Gosper conjectured a few beautiful identities involving Πq and also a few Lambert series identities. Many people have attempted confirming some of those identities in Gosper’s list, mainly by using Gosper’s q-trigonometric identities. In this talk, we either prove or disprove all the Πq and Lambert series identities in Gosper’s list by mainly using S. Ramanujan’s theta function identities and W. N. Bailey’s summation formula. In the process, we obtain three new Gosper kind of identities.
Suzhou University of Science and Technology, China
Title: Identities, Inequalities and Congruences for Odd Ranks and $k$-marked Odd Durfee Symbols
Abstract:
Indian Institute of Technology Gandhinagar, Palaj, Gujarat, India
Title: Extended higher Herglotz functions
Abstract:
Thapar Institute of Engineering & Technology, Patiala, Punjab, India
Title: Enumeration of mock theta functions treating them as q-series
Abstract: In 2004, Ashok Agarwal initiated the study of enumeration of mock theta functions using colored partitions, mock theta functions are the last invention of Ramanujan. Later, Andrews discovery of Lost Notebook triggered an extensive research on mock theta functions. Using different combinatorial tools and analogues work to Agarwal we found various combinatorial interpretations for mock theta functions. We explore mock theta functions as q−series and examine them as generating function of restricted partition functions. In addition to this, we found some basic congruences associated with mock theta functions.
Rajiv Gandhi University, Arunachal Pradesh, India
Title: Partition and colour partition of positive integers
Abstract: We discuss colour partition of the integers and its congruence properties with special reference to Ramanujan’s general partition function.
Indian Institute of Technology Indore, Madhya Pradesh, India
Title: An equivalent criteria for the Riemann hypothesis
Abstract: In 1916, Riesz proved that the Riemann hypothesis is equivalent to the bound associated with the Mobius function. Around the same time, Hardy and Littlewood gave another equivalent criteria for the Riemann hypothesis while correcting an identity of Ramanujan. In this talk, we shall discuss a one-variable generalization of the identity of Hardy and Littlewood and as an application, we provide Riesz-type criteria for the Riemann hypothesis. In particular, we obtain the bound given by Riesz as well as the bound of Hardy and Littlewood. This is joint work with Archit Agarwal and Meghali Garg.
Central University of Tamil Nadu, India
Title: Essence of Optimal Control and Inverse Problems in Biological Models
Abstract: In the first part, we will discuss optimal control theory for cancer treatment followed by an optimal control problem for the acid-mediated cancer invasion model. Initially, we prove the existence of optimal control and then we establish the necessary optimality condition for the acid-mediated cancer invasion model. The second part of the talk is to provide a short review about the inverse problems for PDEs through Carleman estimates followed by the inverse problems for the tumor growth model.
Central University of Kerala, India
Title: Blow-up and Existence of solutions for a class of fourth-order thin-film equation
Abstract: The fourth-order reaction-diffusion equations take an inevitable space in the study of evolution equations. It describes a great number of physical phenomena like thin-film theory, lubrication theory, phase transition, and many other fields. This talk addresses the blow-up and existence of solutions of one of such fourth-order parabolic problems with nonlocal sources and the Neumann boundary condition.
Visvesvaraya National Institute of Technology, Maharashtra, India
Title: High-resolution WENO schemes for compressible flows
Abstract: A modified third and fifth-order weighted essentially non-oscillatory (WENO) schemes for the solution of inviscid compressible flows will be the topic of this talk. A new global-smoothness indicator is devised for the third-order WENO scheme which shows an improved solution behavior over many existing WENO schemes, for the problems which contain discontinuities and attain optimal-order of accuracy at the critical points. The WENO schemes were designed in such a way that the least weights should be given to the most discontinuous sub-stencil, increasing their weights creates oscillations that could prevent the WENO scheme from attaining the expected order of accuracy. Assigning a larger weight to the sub-stencils containing the discontinuity has been studied and suggested improvements in the scheme that could capture the smooth solutions even after increasing the weights of the lesser smooth sub-stencils. Further, we’ll be discussing the problem of independent discontinuity locater for hybridization. The hybrid WENO scheme works on the principle of applying linear upwind scheme in smooth regions and WENO algorithm in non-smooth regions to save computational cost which is reflected in the time taken for the computation of the numerical solution. The discontinuity locater has been designed based on the properties of the existing smoothness indicators, which is problem independent. Numerical experiments have been included to demonstrate the application of the proposed theory to some benchmark problems.
Dalhousie University, Canada
Title: Linked partition ideals and Schur's 1926 partition theorem
Abstract: Issai Schur's famous 1926 partition theorem states that the number of partitions of $n$ into distinct parts congruent to $\pm 1$ modulo $3$ is the same as the number of partitions of $n$ such that every two consecutive parts have a difference at least $3$ and that no two consecutive multiples of $3$ occur as parts. In this talk, we consider some variants of Schur's theorem, especially their Andrews--Gordon type generating functions, from the perspective of span one linked partition ideals introduced by George Andrews. Our investigation has interesting connections with basic hypergeometric series, $q$-difference equations, computer algebra, and so on.
Wuhan University, China
Title: Sign Changes of Coefficients of Powers of the Infinite Borwein Product
Institute for Basic Science, South Korea
Title: Explicit transformations of certain Lambert series