“From Theory to Experiment and Back”Abstract: Axions exist at an exciting intersection between theory and experiment where theory both guides and is guided by experiment.  Axion strings contain information about charge quantization in the form of ’t Hooft anomalies.  Trying to measure charge quantization using axion strings leads directly to a novel approach of analyzing CMB data.  At the same time, experiments … Read More

Abstract: I will describe a scenario in which heavy particles are produced during inflation via their couplings to the inflaton. Following their production, these heavy particles propagate classically and can give rise to localized spots on the Cosmic Microwave Background. Momentum conservation during particle production dictates that these localized spots come in pairs. I will discuss the properties of such … Read More

Cosmological observations of signals from the inflation era offer a unique window into the dynamics at energy scales far beyond the reach of terrestrial experiments. I will discuss possible signals (including CMB, large-scale structure, and gravitational wave) associated with possible particle production and phase transition during the inflation.

There are reasons to believe that consistent quantum gravity theories do not admit exact global symmetries. This claim has surprisingly strong implications, some of which are relevant for particle physics and cosmology. I will discuss some recent variations on this theme, including the absence of Chern-Weil symmetries (with applications to axion physics) and the absence of higher-form symmetries (with implications … Read More

Understanding the fundamental nature of dark matter is one of the major challenges facing the physics community today. Direct and indirect detection efforts search for dark matter interactions with the Standard Model of particle physics, but no concrete evidence has been observed. In this talk, I will discuss how cosmological observables can be used as complementary probes of dark matter … Read More

Axion-like fields are ubiquitous in high-energy physics. Their symmetry properties also make them favored ingredients in many cosmological scenarios ranging from inflation to dark matter. The resonant, nonperturbative decay of these axion-like fields into both standard model and dark photons is a generic feature of these models. In this talk, I discuss the phenomenology of resonant axion decay into gauge … Read More

Axion cosmic strings have for some time been considered a potential source of enhancement of axion dark matter production, and have been the subject of extensive simulations (for references, see out in recent years). But axion strings are rather peculiar entities. This talk will explore some aspects of these objects, and suggest that they are not likely to play a … Read More

Title: The Impact of a Midband Gravitational Wave Experiment On Detectability of Cosmological Stochastic Gravitational Wave BackgroundsAbstract: I will discuss the impact of a future midband gravitational wave experiment on improving detectability of a cosmologically sourced stochastic GW background. Specific proposed midband experiments considered are TianGo, B-DECIGO and AEDGE. We propose a combined power-law integrated sensitivity (CPLS) curve combining GW experiments over different frequency bands, which shows … Read More

Title: Mass, Effective Operators and Locality in the Double Copy Abstract: The double copy is a web of relations between the scattering amplitudes of various quantum field theories. The original example was double-copying Yang-Mills to produce dilaton gravity. This was first discovered as the field theory limit of string theory KLT relations. In this limit, two features of the KLT … Read More