Calendar
- 12March 12, 2023No events
- 13March 13, 2023
CMSA Swampland: String theory scalar potentials and their critical points
20 Garden Street, Cambridge, MA 02138Positive scalar potentials in string effective theories could provide an origin to Dark Energy, responsible for the accelerated expansion of our universe today or during inflation. It is thus crucial to characterise these scalar potentials, namely their slope, their critical points (de Sitter solutions) and the associated stability, as also advocated by the Swampland Program. We will present such characterisations. Going further, we will also discuss negative scalar potentials, and make related observations on anti-de Sitter solutions, in particular on a new mass bound, as well as comments on scale separation.
- 14March 14, 2023
Harvard–MIT Algebraic Geometry Seminar: Higher Tsen Theorem
Tsen’s Theorem gives a simple sufficient criterion for an algebraic variety to have a point over a complex function field. In the talk we shall discuss a way to define on the collection of such points a structure of a stack and show that this stack is homologically contractible. We shall explain a variant of this phenomenon that can be employed for the study of Beilinson-Drinfeld Opers for reductive groups. This is joint work with D. Beraldo and D. Kazhdan.
- 15March 15, 2023No events
- 16March 16, 2023
CMSA Active Matter: Active chemical reactions in phase-separating systems
20 Garden Street, Cambridge, MA 02138Motivated by the existence of membrane-less compartments in the chemically active environment of living cells, I will discuss the dynamics of droplets in the presence of active chemical reactions. Therefore, I will first introduce the underlying interplay between phase separation and active reactions, which can alter the droplet dynamics compared to equilibrium systems. A key feature of such systems is the emergence of concentration gradients even at steady states. In the second part of this talk, I will discuss how these gradients can trigger instabilities in the core of chemically active droplets, giving rise to a new non-equilibrium steady state of liquid spherical shells. Finally, I will present experimental and theoretical results discussing the existence and energetic cost of this non-equilibrium steady state in a coacervate system.
This seminar will be held in person and on Zoom. For more information on how to join, please see: https://cmsa.fas.harvard.edu/event_category/active-matter-seminar/
- 17March 17, 2023
CMSA Quantum Matter in Mathematics and Physics: Tensorial TQFT and disentangling modular Walker-Wang models
20 Garden Street, Cambridge, MA 02138I will introduce simple “tensorial” definitions for many algebraic and categorical structures appearing in the classification of topological phases of matter. Such “tensorial TQFTs” will be defined as maps that associate tensors to geometric/topological objects of some type, subject to gluing axioms. Tensorial TQFTs are very directly related to microscopic physical models in terms of discrete path integrals. I will use those tensorial definitions to construct invertible boundaries which disentangle modular Walker-Wang models.This seminar offers the option to attend by Zoom. For information on how to join, please see:Quantum Matter in Mathematics and Physics (QMMP) 2023:
https://cmsa.fas.harvard.edu/event_category/quantum-matter- seminar/ ——–
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https://forms.gle/1ewa7KeP6BxBuBeRA - 18March 18, 2023No events