90 citations · 461 across the 24 of their papers we have counts for
24 papers
Majoron Dark Matter, High-Scale Seesaw, and Leptogenesis
Brian Batell, Arnab Dasgupta, Swapnil Dutta +1
We study the cosmology and observational probes of majoron dark matter in a high-scale seesaw framework with spontaneously broken lepton number. Right-handed neutrinos naturally ge…
Phasing out Dark Matter Isocurvature with Thermal Misalignment
Brian Batell, Akshay Ghalsasi, Subhajit Ghosh +1
Thermal misalignment provides an alternative to the standard misalignment mechanism for the cosmological production of scalar dark matter. In this framework, feeble couplings to pa…
-incidental -naturalness
Brian Batell, Akshay Ghalsasi, Wenjie Huang +1
-naturalness is a novel solution to the electroweak hierarchy problem which posits copies of the Standard Model with varying Higgs mass-squared parameters. Reheating proceed…
Enhanced Matter Power Spectrum from Axion Kination after Big Bang Nucleosynthesis
Raymond T. Co, Nicolas Fernandez, Akshay Ghalsasi +2
Despite stringent constraints from Big Bang Nucleosynthesis (BBN) and cosmic microwave background (CMB) observations, it is still possible for well-motivated particle physics model…
Acoustic Misalignment Mechanism for Axion Dark Matter
Arushi Bodas, Raymond T. Co, Akshay Ghalsasi +2
A rotation in the field space of a complex scalar field corresponds to a Bose-Einstein condensation of charges. We point out that fluctuations in this rotating condensate ex…
Conversations and Deliberations: Non-Standard Cosmological Epochs and Expansion Histories
Brian Batell, Keith R. Dienes, Brooks Thomas +17
This document summarizes the discussions which took place during the PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pen…
Axion baryogenesis puts a new spin on the Hubble tension
Raymond T. Co, Nicolas Fernandez, Akshay Ghalsasi +2
We show that a rotating axion field that makes a transition from a matter-like equation of state to a kination-like equation of state around the epoch of recombination can signific…
Amplifying the Chirp: Using Deep Learning (U-Nets) to filter signal from noise in LIGO data
Akshay Ghalsasi
The direct detection of gravitational waves by LIGO has heralded a new era for astronomy and physics. Typically the gravitational waves observed by LIGO are dominated by noise. In…
Gravitational Waves from Nnaturalness
Brian Batell, Akshay Ghalsasi, Matthew Low +1
We study the prospects for probing the Nnaturalness solution to the electroweak hierarchy problem with future gravitational wave observatories. Nnaturalness, in its simplest incarn…
Dynamics of Dark Matter Misalignment Through the Higgs Portal
Brian Batell, Akshay Ghalsasi, Mudit Rai
A light singlet scalar field feebly coupled through the super-renormalizable Higgs portal provides a minimal and well-motivated realization of ultra-light bosonic dark matter. We s…
Dark Black Holes in the Mass Gap
Nicolas Fernandez, Akshay Ghalsasi, Stefano Profumo +2
In the standard picture of stellar evolution, pair-instability -- the energy loss in stellar cores due to electron-positron pair production -- is predicted to prevent the collapse…
New Horizons: Scalar and Vector Ultralight Dark Matter
D. Antypas, A. Banerjee, C. Bartram +123
The last decade has seen unprecedented effort in dark matter model building at all mass scales coupled with the design of numerous new detection strategies. Transformative advances…
New Ideas in Baryogenesis: A Snowmass White Paper
Gilly Elor, Julia Harz, Seyda Ipek +21
The Standard Model of Particle Physics cannot explain the observed baryon asymmetry of the Universe. This observation is a clear sign of new physics beyond the Standard Model. Ther…
Thermal Misalignment of Scalar Dark Matter
Brian Batell, Akshay Ghalsasi
The conventional misalignment mechanism for scalar dark matter depends on the initial field value, which governs the oscillation amplitude and present-day abundance. We present a m…
Gravitational Wave and CMB Probes of Axion Kination
Raymond T. Co, David Dunsky, Nicolas Fernandez +4
Rotations of an axion field in field space provide a natural origin for an era of kination domination, where the energy density is dominated by the kinetic term of the axion field,…
Comments on Axions, Domain Walls, and Cosmic Strings
Michael Dine, Nicolas Fernandez, Akshay Ghalsasi +1
Axions have for some time been considered a plausible candidate for dark matter. They can be produced through misalignment, but it has been argued that when inflation occurs before…
Lepto-Axiogenesis
Raymond T. Co, Nicolas Fernandez, Akshay Ghalsasi +2
We propose a baryogenenesis mechanism that uses a rotating condensate of a Peccei-Quinn (PQ) symmetry breaking field and the dimension-five operator that gives Majorana neutrino ma…
Reinterpretation of LHC Results for New Physics: Status and Recommendations after Run 2
Waleed Abdallah, Shehu AbdusSalam, Azar Ahmadov +139
We report on the status of efforts to improve the reinterpretation of searches and measurements at the LHC in terms of models for new physics, in the context of the LHC Reinterpret…
Superradiance and the Spins of Black Holes from LIGO and X-ray binaries
Nicolas Fernandez, Akshay Ghalsasi, Stefano Profumo
Measurements of the spin of stellar mass black holes (BHs) are now possible both through LIGO observations of binary BH mergers and for BHs in X-ray binary systems. The spins of BH…
Light Dark Matter from Entropy Dilution
Jared A. Evans, Akshay Ghalsasi, Stefania Gori +2
We show that a thermal relic which decouples from the standard model (SM) plasma while relativistic can be a viable dark matter (DM) candidate, if the decoupling is followed by a p…
Exploring the astrophysics of dark atoms
Akshay Ghalsasi, Matthew McQuinn
A component of the dark matter could consist of two darkly charged particles with a large mass ratio and a massless force carrier. This `atomic' dark sector could behave much like…
Probing nonstandard neutrino cosmology with terrestrial neutrino experiments
Akshay Ghalsasi, David McKeen, Ann E. Nelson
Neutrino masses and the number of light neutrino species can be tested in a variety of laboratory experiments and also can be constrained by particle astrophysics and precision cos…
Baryogenesis via Mesino Oscillations
Akshay Ghalsasi, David McKeen, Ann E. Nelson
We propose a new mechanism for baryogenesis at the 1-200 MeV scale. Enhancement of CP violation takes place via interference between oscillations and decays of mesinos--bound state…
Effects of Mass Varying Neutrinos on Cosmological Parameters as determined from the Cosmic Microwave Background
Akshay Ghalsasi, Ann E. Nelson
In models with a light scalar field (the `acceleron') coupled to neutrinos, neutrino masses depend on neutrino density. The resulting coupled system of mass varying neutrinos (MaVa…