Events Daily

Friday, November 19, 2021
      

Oscillons: Gravitational waves, multi-field generalizations and quantum radiation
Evangelos Sfakianakis, Massachusetts Institute of Technology
Event Type: Special Seminar
Time: 3:00 PM - 4:00 PM
Location: 726 Broadway, 902, Lg Conf
Abstract: Beyond single-field oscillons: Oscillons are ubiquitous in scalar field models where the potential is shallower than quadratic away from the origin. They have been shown to arise naturally after inflation with plateau or axion monodromy potentials and their formation is accompanied by the emission of gravitational waves. I will show how the spectrum of GW’s retains the memory of oscillon formation in some cases, providing a first tool —at least in principle— of probing the inflationary potential around the origin. Despite the wide belief that multiple fields are present in the early universe, oscillon studies have largely relied on single-field models. I will describe a first step towards understanding multi-field oscillons, albeit in a simple highly symmetric model. Finally, I will discuss how quantum radiation can affect the formation and decay of oscillons and breathers. I will show how one can use the Classical-Quantum-Correspondence to simulate the collision of solitons in the one-dimensional Sine-Gordon potential and how quantum radiation can lead to the formation of breathers and their subsequent decay.

Taxonomy of Brane Gravity Localizations and Covert Symmetry Breaking
Christopher Erickson, Imperial College London
Event Type: Informal HEP Talk
Time: 4:00 PM - 5:00 PM
Location: 726 Broadway, 940, CCPP Seminar
Abstract: We study how to derive lower-dimensional effective physics dimensionally reducing on a non-compact transverse space. We find there are three different types of solution, depending crucially on the boundary conditions at the brane worldvolume. Genuinely lower-dimensional far-fields are shown to be compatible with higher-dimensional near-fields, given a boundary condition consistent with a non-constant transverse zero mode. We present a linear example in the context of Type IIA SUGRA. Next, we explore the effective field theory of such non-constant transverse zero mode. Specifically, we discover that the typical relationship between cubic and quartic terms in gauge theories is violated, and we find a massless, but gauge fixed, effective field theory in the lower dimension. We dub this Covert Symmetry Breaking.

Intellectually Stimulating Craic
Iraj Eshghi, New York University
Event Type: Other
Time: 6:00 PM - 8:00 PM
Location: 726 Broadway, 940, CCPP Seminar