Finding unconventional superconductors in proximity to various strongly correlated electronic phases has been a recurring theme in materials as diverse as heavy fermion compounds, cuprates, pnictides, and twisted bilayer graphene. The recent discovery of superconductivity in layered nickelates1 was motivated by looking for an analog of the…

We show that if a massive body is put in a quantum superposition of spatially separated states, the mere presence of a black hole in the vicinity of the body will eventually destroy the coherence of the superposition. This occurs because, in effect, the black hole acquires "which path" information…

Galaxy-galaxy strong lensing involves a foreground galaxy producing multiple distorted and highly magnified images of a background galaxy. Smaller perturbers, which can be either subhalos orbiting the foreground galaxy or halos along the line-of-sight, cause slight deviations in these bright arcs. For this reason, strong gravitational lenses…

 I will discuss the potential importance of a dark-sector phase transition in the early universe in setting the measured relic abundance, for a simple scenario with strongly interacting dark matter. Enhancement of the dark matter density within shrinking pockets of the high-temperature phase leads to a dramatic reduction…

Abstract:

The Event Horizon Telescope has released total intensity images of the Messier 87* and Sagittarius A* accretion flows; polarized images have been released for M 87*, and are imminent for Sgr A*. These images are a rich source of theoretical constraints on the black hole accretion flow system, but a trustworthy measurement of…

For each prime number p, there exists a p-adic version of the Veneziano amplitude and its higher-point generalizations. Multiplying together all the p-adic amplitudes and their real counterparts, one obtains the adelic amplitudes, objects intended to join together string theory and analytic number theory.

In this talk I will provide a…

Abstract: Twisted van der Waals materials provide a new venue to explore flat electronic bands and the interaction-driven states they host. While many such phases have been reported, little is known about their excitations or how they depend on externally applied fields. In this talk, I will present two examples where…

On behalf of the Dicke Fellowship organizing committee

We are pleased to announce that the 2nd annual Dicke Fellowship Symposium is scheduled for September 29th. This one-day event will take place in Jadwin Hall (PCTS room 407) and feature talks from current and former Dicke Fellows on their research. We are also delighted to have…

Quantum mean-field spin models of Lipkin-Meshkov-Glick or Curie-Weiss type generically exhibit a spectral gap in the ferromagnetic parameter regime. In this talk, I will explain semiclassical criteria for the presence of a spectral gap in such models and present formulas for their value alongside a complete description of the…

Pure 3d gravity in AdS has only boundary degrees of freedom. I will show that these interact nontrivially if spacetime is restricted to a finite size. Their dynamics can be obtained equivalently by TTbar deforming the infinite volume theory. We can canonically quantize the gravitational side and, after a field redefinition, find a simple…

Measurement of natural systems typically involves perturbation and interpretation. In this talk, I will discuss the implications of measurement in the context of RNA in gene expression in human cells. I will focus on measurements of RNA biology using high-throughput sequencing, which are powerful for their scale but also involve perturbations…

D-instanton induced S-matrix in type 0B string theory in two dimensions suffers from infrared divergences. This can be traced to the fact that these processes produce low energy rolling tachyon states that cannot be regarded as linear combination of finite number of closed string states. We compute semi-inclusive cross sections in this theory…

QCD axions and Dark Matter Radio

The QCD axion, originally posed a solution to the strong CP problem, is among the most compelling candidates in the hunt for dark matter. The last decade has seen the emergence of several new ideas to search for axion dark matter. In this talk, I overview the landscape of…

In this talk, we will consider line defects (one-dimensional defects) in CFTs. Such systems are of relevance to various physical systems, with applications ranging from condensed matter physics to conformal gauge theories. I will review some general properties of line defects in CFTs, especially in the context of RG flows on line defects, where…

Abstract: In holographic duality an eternal AdS black hole is described by two copies of the boundary CFT in the thermal field double state. We provide explicit constructions in the boundary theory of infalling time evolutions which can take bulk observers behind the horizon. The constructions…