seminars during March 3 to 7

Next week the following seminars are scheduled.

Year-long programme in Topology
------------------------------
Title : 3 manifolds,
Speaker : A.R.Shastri,
Time : 5:15 - 6:15 pm,
Venue : Room no 113,
Date : 3/3/2008 (monday) and 5/3/2008 (wednesday)

Tony

Convener
SCC

update

Todays additional colloquium is at 5:15 pm and not at 4:40 pm as
previously announced

Additional Colloquium

We have one more Colloquium this week. Msc students/Research scholars are
encouraged to attend

Department Colloquium
=====================

Speaker: Prof. Mario Ahues, LAMUSE,
Department of Mathematics
University of St-Etienne, France

Title: Iterative Refinement: Theory and Applications

Venue: Ramanujan Hall

Time: 4:40pm to 5:40 pm
Date: 28 Feb
Abstract:

If an abstract problem is put in the form of a functional
equation and if a numerical algorithm is available to produce an
initial approximation of the exact solution, then a sequence of
approximations can be built using only the numerical algorithm. Under
rather mild hypotheses, this sequence of approximations
is convergent to the exact solution of the abstract problem. Some examples
of specific application are: linear and nonlinear integral
equations including eigenvalue problems, computation of the Hermitian
positive definite square root of an Hermitian positive definite matrix and
Sylvester equations.

seminars during Feb 25-29

We have five talks during the week Feb 25-29

1.
Colloquium talk:
----------------
Speaker: A. Joseph Kennedy
Title: Combinatorial Representation Theory
Date: February 26, 2008 (Tuesday)
Time: 4:30 to 5:30 pm
Venue: Ramanujan Hall

Abstract:

Let G be a group of linear transformations on a finite
dimensional vector space V. Then G acts diagonally on
V^k, the k-th tensor power of V. The basic problem is
to know how does V^k decompose into irreducible
representations of G. One way of studying this problem
is to consider the algebra of all linear
transformation on V^k that commute with the G-action,
called centralizer algebra of G. A large class of
Diagram algebras (whose basis consist of diagrams with
certain multiplication) arises in this way as the
centralizer algebras of different groups. This
provides the connection between the representation
theory and related combinatorics. The main part of
this talk is to discuss this aspect in detail.

2.
Seminar talk:
---------------
Speaker: A. Joseph Kennedy
Title: Partition Algebras
Date: February 28, 2008 (Thursday)
Time: Time 3 to 4 pm
venue: room no 105

Abstract:

In the early 1990's, the partition algebra appeared
independently in the works of P. Martin and V. F. R.
Jones. Their work on the partition algebra stemmed
from studies of Potts models and related problems in
statistical mechanics. In 1993, Jones considered the
partition algebra P_k(n) as the centralizer algebra of
the symmetric group S_n acting on V^k, where V is the
permutation module for S_n. This talk mainly
discusses the above work and its continuation by me.

3.
Popular Lecture Series Talk
----------------------------
Speaker: Professor Jaikumar Radhakrishnan
School of Technology and Computer Science
Tata Institute of Fundamental Research, Mumbai
Title: List-decoding Reed-Solomon codes
Date: 29 February 2008
Time: 5:05-6 pm
Venue: Ramanujan Hall

Abstract: We will introduce the notion of list-decoding, and
discuss the list-decoding algorithms of Sudan, and Guruswami &
Sudan for list-decoding Reed-Solomon codes. We will then describe
some results on the limits of list-decoding. The talk will
involve mainly linear algebra and should be accessible to a
general mathematical audience.

4&5.
Year-Long Programme in Topology
-------------------------------
Speaker : A.R. Shastri,
Topic : 3 - manifolds,
venue : room no 113,
Days : Monday (25/02/2008) and Wednesday (27/02/2008)
Time : 5:15 - 6:15 pm

Thanks

Tony J. Puthenpurakal
Convener
SCC

Re: Maths Dept Seminar and colloquium for the week Jan28 toFeb3

Update

Prof. P. Zvengrowski's colloquium "Riemann and his Zeta Function"
will be held from 4:30 to 5:30 and not at 4 to 5 as announced earlier.

Thanks

Tony

Maths Dept Seminar and colloquium for the week Jan28 toFeb3

We have three department colloquiums and two seminars for the week Jan28
toFeb3

1. Title: Real Elements in Spin Groups
Speaker: Anupam Kumar Singh,
IMSc, Chennai
Venue: Ramanujan Hall
Date: Jan 28
Time: 4 to 5pm
Abstract: Let $G$ be an algebraic group defined over a field $k$. We call
an element $t$ in $G(k)$ real if there exists $g$ in $G(k)$ such that
$gtg^{-1}=t^{-1}$. The question is to classify real elements in a
Semisimple Algebraic Group. In this talk, along with known results, we
sketch the proof in the case of Spin groups.

2. Title: Spectrum and Arithmetic
Speaker: Professor C. S. Rajan,
TIFR Mumbai
Venue: Ramanujan Hall
Time: 4 to 5pm
Date: Jan 29

Abstract: We will discuss the relationship between spectrum and arithmetic
especially in the context of locally symmetric spaces. In this context we
raise some conjectures and give some partial evidence that the arithmetic
and the spectrum of such spaces should mutually determine each other.

3. Title: Riemann and his Zeta Function
Speaker: P. Zvengrowski
University of Calgary
Venue: Ramanujan Hall
Time: 4 to 5pm
Date: Jan 31
Abstract:
This talk will take an historical/mathematical perspective to the
Riemann zeta function $\zeta(s)$
and the famed Riemann Hypothesis (RH), generally considered the most
important and probably most difficult unsolved question in
mathematics. Riemann wrote a single paper of just 8 pages on the
subject, in 1859. The RH is stated there but
it is not at all clear from this paper tha
(a) Riemann thought it was important,
(b) Riemann had any evidence whatsoever to make his conjecture.
Some sixty odd years after his death answers to these questions became
clearer,
thanks to an exhaustive two year study of Riemann's unpublished notes
by Karl
Ludwig Siegel. In this talk we shall examine the methods that Riemann
had
likely used to study the zeros of $\zeta(s)$, compute a few zeros
ourselves by these very same methods, and if time permits mention
briefly some of the major developments
since the time of Siegel's study.

4. Title : Vector bundles, flag manifolds and Stiefel manifolfds
Speaker : Peter Zvengrowski
Venue : Room no 113, Maths Department,
Time : 5:00 - 6:15 pm,
Date : 28/01/2008 (monday) and 30/01/2008 (wednesday)

Abstract

In this seminar we shall start we an introduction to vector bundles, from
the definition and a few examples to some of the basic properties. The
example of most interest to us will be the tangent bundle of a smooth
manifold. This will be studied first (briefly) for the case of a flag
manifold, following K.Y.Lam. Then the special case of Stiefel manifolds
will be examined in some detail, including the theorem of Sutherland that
$V_{n,r}$ is parallelizable (has trivial tangent bundle) for $r \geq 2$.
The associated projective Stiefel manifolds $X_{n,r}$ will also be
studied. An attempt will be made to keep the lectures as self contained as
possible, although the techniques used range from geometry to homotopy
theory to K-theory.

Tony J. Puthenpurakal
Convener
SCC