The model for measurements used in quantum mechanics (based on the projection postulate) cannot be extended to model measurements of quantum fields, since they are incompatible with relativity. We will see that measurements performed with particle detectors (i.e., localized non-relativistic quantum systems that couple covariantly to quantum fields) are consistent with relativity, and that they...
We present broadly applicable nonperturbative results on the behavior of eigenvalues and eigenvectors under the addition of self adjoint operators and under the multiplication of unitary operators, infinite dimensional Hilbert spaces. To this end, we decompose these operations into elementary 1 parameter processes in which the eigenvalues move similarly to the spheres in Newton’s cradle. As...
Quantum counterparts to classical black holes provide an exciting ground for phenomenology of quantum gravity. Within the functional renormalization group approach to quantum gravity, we propose a novel method to account for quantum effects in classical spacetimes. At the core of our construction is decoupling mechanism: when a physical low-energy scale overcomes the effect of the artificial...
A central open problem of quantum physics is to reconcile theory with experience. In this work I present a framework for studying distinct modes of experience in a superposed world. A mode of experience is characterized by how the world, experiences, and options relate to each other by the perceptions, decisions, and actions, as well as by probabilistic rules encoding probabilistic or...
While we do not have a final theory of quantum gravity, we have learned valuable lessons from investigations on how gravity affects quantum properties of matter and vice versa. In this talk, I will review a paper that claims that entangled and separable states affect spacetime curvature differently. I will present the proposed setup and show a particular case. Then, I will argue that the...
Particle physics and direct detection experiments have yielded null results for dark matter. As a result, interest is growing in theories in which dark matter lives in a hidden sector coupled only weakly to the Standard Model. Many hidden sector theories involve an epoch of matter domination in the very early Universe, deviating from the story of standard Lambda-CDM cosmology. Dark matter...
There is theoretical motivation for particles beyond those we have so far discovered. Our observations of the universe suggest there must be some ‘dark matter’ or matter whose content we don’t understand. Bosons with very small mass (10−13eV) can form oscillating clouds around black holes. These clouds would emit gravitational waves. Here, I’ll present some developments of theoretical...
Cosmological models are used to describe our universe and their free parameters can be constrained by observations. However, these constraints are reliant on the precision of our data analysis. A major issue in cosmology is that high- and low-redshift measurements significantly disagree on the value of certain parameters, such as the Hubble constant H0. By improving our statistical analysis,...
The hypothetical QCD axion particle is one of the best motivated dark matter candidates. In this talk I will outline the motivation for the QCD axion, and discuss how we could look for this elusive particle by searching for the new forces that it would mediate. I will describe an existing experimental setup to look for these new forces based on the technique of nuclear magnetic resonance, and...
To describe the full universal low-energy physics of metals, it is necessary to include all gapless modes around the Fermi surface. In this talk, we study the non-Fermi liquid state that arises at the antiferromagnetic quantum critical point in two space dimensions through a novel field-theoretic functional renormalization group scheme. In this theory, critical spin fluctuations destroy the...
Noncommuting conserved quantities have recently launched a subfield of quantum thermodynamics. In conventional thermodynamics, a system of interest and an environment exchange quantities energy, particles, electric charge, etc. that are globally conserved and are represented by Hermitian operators. These operators were implicitly assumed to commute with each other, until a few years ago....
SUSY QFT’s are of long-standing interest for their high degree of solvability (due in part to the power of BPS quantities) and phenomenological implications. The holomorphic twist produces a new theory which precisely isolates the BPS operators which give the SUSY QFT its potency. I will describe how this twist is performed; the algebraic structure of the twisted theory; and three surprising...
In this talk I will give a brief overview of a generalisation of Fedosov quantization, a type of deformation quantization, to the chiral setting. In particular I will outline a geometric approach to chiral quantization using Gelfand-Khazdan formal geometry, introduced by Gorbounov, Gwilliam and Williams, which makes use of the fact that the local observables of the curved beta-gamma system...
Over the past decade, many infrared phenomena of gauge theories, such as soft theorems and memory effects, have been shown to be manifestations of asymptotic symmetries which persist to the spacetime boundary. In this talk, I will discuss ongoing work, in collaboration with Robert Myers and Ana-Maria Raclariu, which recasts the asymptotic symmetries of gauge theories in Minkowski spacetime...
