Date and Time: Tuesday 12 November, 5:00 pm - 6:30 pm.
Venue: Room 215, Department of Mathematics.
Title: Higgs bundles and the Hitchin fibration - II.
Abstract: We will introduce Higgs bundles on curves, discuss the Hitchin
fibration and its fibers in terms of spectral curves.
Time:
3:00pm-4:00pm
Location:
Ramanujan Hall, Department of Mathematics
Description:
Partial Differential Equations seminar.
Speaker: Arnab Roy.
Affiliation: INRIA, Nancy.
Date and Time: Wednesday 13 November, 3:00 pm - 4:00 pm.
Venue: Ramanujan Hall, Department of Mathematics.
Title: Stabilization of a rigid body moving in a compressible viscous fluid.
Abstract: In this talk, we discuss the stabilization of a fluid-structure
interaction system of a viscous, compressible fluid and rigid ball in a
three dimension space with an external force acting on the ball produced
by a spring and a damper connecting the centre of the ball to a fixed
point $h_1$. We prove global-in-time existence result for this model under
the condition that the initial velocities are small and the center of mass
of the body is sufficiently near to $h_1$. In this scenario, we discuss
the asymptotic behaviour of the whole system.
Time:
4:00pm
Location:
Ramanujan Hall, Department of Mathematics
Description:
Algebraic geometry seminar.
Speaker: Chandranandan Gangopadhyay.
Affiliation: The Institute of Mathematical Sciences, Chennai.
Date and Time: Wednesday 13 November, 4:00 pm - 5:00 pm.
Venue: Ramanujan Hall, Department of Mathematics.
Title: Quot schemes and Semistable Vector Bundles.
Abstract: Let C be a smooth projective curve over an algebraically closed
field k. Fix r, d ≥ 1. Let Q(r, d)
be the quot scheme parametrizing degree d torsion quotients of the trivial
vector bundle of rank r. Then we show that the universal
kernel bundle over C × Q(r, d) and its pushforward to Q(r, d) are stable
with respect to certain
natural ample bundles over C × Q(r, d) and Q(r, d) respectively.
Time:
4:30pm-5:30pm
Location:
Ramanujan Hall, Department of Mathematics
Description:
CACAAG seminar.
Speaker: Trygve Johnsen.
Affiliation: The Artic University of Norway.
Date and time: Friday 15 November, 4:30 pm - 5:30 pm.
Venue: Ramanujan Hall, Department of Mathematics.
Title: Greedy weights for codes and matroids.
Abstract: Greedy weights of linear codes measure the minimal support
cardinality
of chains of subcodes for a certain lexicographic order. We show how the
problem
of finding such weights can be studied by inspecting the poset of flats of
the generator matroid, or better: the (dual) poset of cycles for the
parity check matroid. The terms of a minimal resolution of the
Stanley-Reisner ring of the independence complex of the parity check
corresponds to the points of the poset. Optimal paths in the poset
diagram, and optimal chains of non-zero component maps in a minimal
resolution of the Stanley-Reisner ring. correspond to greedy weights Such
maps can be constructed using poset homology, or studied indirectly,
through the Taylor complex, which also provides a resolution, although
not minimal.