Organizers: Anna Marie Bohmann, Rares Rasdeaconu, Ioana Suvaina
Speaker:
Victor Vuletescu (University of Bucharest, Romania)
Title: Locally conformally Kahler metrics
Abstract:
Locally conformally Kahler metrics (LCK) were
introduced by Izu Vaisman in the mid 70's as a substitute
for
Kahler ones on manifolds which do not admit such metrics
(e.g. Hopf surfaces). By the subsequent work of many people
in the next three decades, this kind of metrics were proven
to exist on a large class of manifolds: for instance,
"virtually all"
compact complex non-Kahler surfaces admit LCK metrics. The
aim of this talk is to give a "state of the art" on the
complex
structure of manifolds admitting LCK metrics, from the
viewpoint of classification theory of
(low-dimensional) compact
complex manifolds. (Contact
person: Rares Rasdeaconu)
Speaker:
Andrei Caldararu (University of Wisconsin, Madison)
Title: Yet another Moonshine
Abstract: The
j-function, introduced by Felix Klein in 1879, is an
essential ingredient in the study of elliptic curves. It is
Z-periodic on the complex upper half-plane, so it admits a
Fourier expansion. The original Monstrous Moonshine
conjecture,
due to McKay and Conway/Norton in the 1980s, relates the
Fourier coefficients of the j-function around the cusp to
dimensions
of irreducible representations of the Monster simple group.
It was proved by Borcherds in 1992. In my talk I will try
to give
a rudimentary introduction to modular forms, explain
Monstrous Moonshine, and discuss a new version of it
obtained in joint
work with Yunfan He and Shengyuan Huang. Our version
involves studying the j-function around CM points (so-called
Landau-Ginzburg points in the physics literature) and
expanding with respect to a coordinate which arises
naturally in string theory.
Speaker:
Manuel Rivera (Purdue University)
Title: An algebraic model for the free loop space
Abstract: In this talk, I will
describe a purely algebraic construction that models
the passage from a topological space X to its free
loop space LX, the space of all continuous maps from
the circle to X, based on an algebraic model for the
underlying space X.
The construction has the advantage that it
does not require any restrictions on the fundamental
group, as other similar constructions
in the literature do.The construction to be discussed is a
modified version of the coHochschild complex. The input is a coalgebra
over a ring equipped with additional structure and the
output a chain complex with a "rotation" operator.
When this
construction
is applied to the coalgebra of chains, suitably
interpreted, of an arbitrary simplicial set S one obtains
a chain complex quasi-isomorphic
to the chains on the free loop space of the geometric
realization of S with its circle action. This algebraic
construction is invariant
with respect to a notion of weak equivalence between
coalgebras that enjoys enough homotopical flexibility to
produce tractable models
for the free loop space of a non-simply connected space. (Contact Person: Anna Marie Bohmann)
Speaker:
Ronan Conlon (University of Texas at
Dallas)
Title: Asymptotically conical Calabi-Yau manifolds
Abstract:
Asymptotically conical Calabi-Yau manifolds are
non-compact Ricci-flat Kahler manifolds that are modelled
on a Ricci-flat
Kahler cone at infinity. I will present a classification
result for such manifolds. This is joint work with
Hans-Joachim Hein (Fordham/Muenster).
(Contact person: Rares Rasdeaconu)