First order phase transitions can leave relic pockets of false vacua and their particles, that manifest as macroscopic Dark Matter. I present one predictive model: a gauge theory with a dark quark relic heavier than the confinement scale. During the first order phase transition to confinement, dark quarks remain in the false vacuum and get compressed, forming Fermi balls that … Read More
Early Universe phenomena are an open window to the study of particle physics at energy scales that cannot be reached in ground-based experiments. These phenomena, however, are characterized by the presence of large non-linearities, limiting the use of analytical techniques to obtain precise predictions. One example is cosmic strings. These are one-dimensional topological defects that generate after phase transitions in … Read More
Abstract: “I will describe an attractive extension of the standard model based on quark-lepton unification. This theory is one of the few options to extend the SM gauge symmetry group via one step breaking, and given its economic matter content and its predictive capabilities, it is worth exploring. The advantages and appeal of this theory will be discussed, emphasizing on its … Read More
Abstract: The near equality of the dark matter and baryon energy densities is a remarkable coincidence, especially when one realizes that the baryon mass is exponentially sensitive to UV parameters in the form of dimensional transmutations. We explore a new dynamical mechanism, where in the presence of an arbitrary number density of baryons and dark matter, a scalar adjusts the … Read More
ABSTRACT: The phenomenon of cosmological gravitational particle production (CGPP) occurs during and after inflation as light fields “feel” the cosmological expansion and their mode functions evolve non-adiabatically. CGPP is a compelling and minimal explanation for the origin of dark matter, which might only interact gravitationally, as well as other cosmological relics. Various studies have explored CGPP for massive particles with spin … Read More
TITLE: Gravitational Portals and Particle Production during Reheating ABSTRACT: For many applications, reheating after inflation can be treated as a (nearly) instantaneous process. However, it is not, and the evolution of the inflaton condensate and the emerging radiation bath may play a role in particle production.The production of matter and radiation during reheating after inflation is considered with an emphasis … Read More
In this talk, I will present our recent proposal of searching for axion dark matter with an optomechanical cavity filled with a material such as superfluid helium. Axion absorption converts a pump laser photon to a photon plus a phonon. The axion absorption rate is enhanced by the high occupation number of coherent photons and phonons in the cavity, allowing … Read More
Abstract: The simplest single-field inflationmodels capture all the relevant contributions to the patterns in the CosmicMicrowave Background (CMB) observed today. A key assumption in these models isthat the quantum inflationary fluctuations that source such patterns aregenerated by a particular quantum state—the Bunch-Davies (BD) state. While thisis a well-motivated choice from a theoretical perspective, the question arisesof whether current data can … Read More
Title: On the Dynamical Origin of the η′ Potential and the Axion Mass Abstract: The standard lore posits that pure QCD dynamics generates a confining potential with a branched structure as a function of the θ angle. This same potential also largely determines the properties of the η′, the (would-be) Goldstone boson associated with the anomalous axial U(1) symmetry of QCD, … Read More
The axion is a strongly theoretically motivated particle. The axion coupling to electromagnetism leads tomany interesting phenomena, providing possibilities for their direct or indirect detection. On the direct detectionside, we propose a new experimental target: axions emitted in the magnetosphere of pulsars. The signal is emittedat the pulsar rotation frequency and is highly coherent. Thus, experimental searches benefit from a … Read More