Fri, 11 Apr 2025
12:00
L4

Matrix models and the amplitude/Wilson loop duality

Atul Sharma
(Harvard)
Abstract
I will describe "open-closed-open triality" in the computation of a (holomorphic) Wilson loop correlator in self-dual N=4 SYM uplifted to twistor space. By the amplitude/Wilson loop duality, this generates a matrix model that computes tree amplitudes in N=4 SYM. I will also describe hopes of embedding this matrix model into twisted holography. In particular, I will present a top-down gravitational dual to self-dual N=4 SYM.
 
Wrinkling of a bilayer with spatially-varying stiffness: from wrinkle branching to cascades
Vella, D O'Kiely, D (01 Jan 2025)
Tue, 03 Jun 2025
15:00
L5

Proper versus trivial actions on Lp-spaces

Indira Chatterji
Abstract

Property (T) (respectively aTmenability) is equivalent to admitting only a trivial action (respectively, a proper action) on a median space, and is also equivalent to admitting only a trivial action (respectively, a proper action) on a Hilbert space (so some L2). For p>2 I will investigate an analogous equivalent characterisation.

Tue, 17 Jun 2025
15:00
L6

Density of Green metrics for hyperbolic groups

Didac Martinez-Granado
Abstract
I will present the "space of metrics of a group'', a metric space parameterizing the geometric actions of
an arbitrary hyperbolic group on Gromov hyperbolic spaces. Even for the surface group case, this space is much larger than
the classical Teichmüller space, encompassing negatively curved Riemannian metrics, geodesic currents,
random walks, and more. I will discuss how Green metrics—those associated with admissible random walks on the group—are dense in
 the space of metrics.  This is joint work in progress with Stephen Cantrell and Eduardo Reyes.
Tue, 03 Jun 2025
15:00
L5

TBC

Tue, 13 May 2025
15:00
L6

From Teichmüller space to Outer space: on the geometry of handlebody groups

Ric Wade
Abstract

The mapping class group a solid handlebody of genus g sits between mapping class groups of surfaces and Out(F_n), in the sense there is an injective map to the mapping class group of the boundary and a surjective map to Out(F_g) via the action on the fundamental group. Similar behaviour happens with actions on associated spaces, such curve complexes and Teichmuller space. I’ll give an expository talk on this, partly in the context of our proof with Petersen that handlebody groups are virtual duality groups, and partly in the context of a problem list on handlebody groups written with Andrew, Hensel, and Hughes.

Theoretical Foundations of Deep Selective State-Space Models
Cirone, N Orvieto, A Walker, B Salvi, C Lyons, T Advances in Neural Information Processing Systems volume 37 (01 Jan 2024)
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