A5017631398- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- History and Developments in Astronomy
- Historical Astronomy and Related Studies
- History of Science and Medicine
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Computational Physics and Python Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Neutrino Physics Research
- Image and Signal Denoising Methods
- Advanced Thermodynamics and Statistical Mechanics
- Atomic and Subatomic Physics Research
- Biofield Effects and Biophysics
- Distributed and Parallel Computing Systems
- Relativity and Gravitational Theory
- Earth Systems and Cosmic Evolution
- Scientific Computing and Data Management
- Black Holes and Theoretical Physics
University of California, Santa Cruz
2019-2024
University of Pittsburgh
2021-2024
University of Cincinnati
2018
University of Washington
2014-2017
A bstract Rotations of an axion field in space provide a natural origin for era kination domination, where the energy density is dominated by kinetic term field, preceded early matter domination. Remarkably, no entropy produced at end domination and hence these eras may occur even after Big Bang Nucleosynthesis. We derive constraints on from both cosmic microwave background investigate how this cosmological scenario affects spectrum possible primordial gravitational waves find that features...
Abstract In the standard picture of stellar evolution, pair-instability — energy loss in cores due to electron-positron pair production is predicted prevent collapse massive stars into black holes with mass range between approximately 50 and 130 solar masses a known as “ hole gap ”. LIGO Virgo detection binary mergers containing one or both this thus challenges picture, possibly pointing an unexpected merger history, unanticipated poorly understood astrophysical mechanisms, new physics....
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 quantum technologies have led to a plethora high-precision sensors and strategies for ultralight ($<10\,$eV) bosonic that can be described by an oscillating classical, largely coherent field. This white paper focuses on searches wavelike scalar vector candidates.
The conventional misalignment mechanism for scalar dark matter depends on the initial field value, which governs oscillation amplitude and present-day abundance. We discuss a by feeble coupling of to fermion in thermal equilibrium drives toward its high-temperature potential minimum at large values, dynamically generating before oscillations begin. Unlike production, abundance is dictated microphysics not conditions. As an application generic mechanism, we realistic scenario couples muon.
We report on the status of efforts to improve reinterpretation searches and measurements at LHC in terms models for new physics, context Reinterpretation Forum. detail current experimental offerings direct particles, measurements, technical implementations Open Data, provide a set recommendations further improving presentation results order better enable future. also brief description existing software frameworks recent global analyses physics that make use data.
A bstract We propose a baryogenenesis mechanism that uses rotating condensate of Peccei-Quinn (PQ) symmetry breaking field and the dimension-five operator gives Majorana neutrino masses. The rotation induces charge asymmetries for Higgs boson lepton chirality through sphaleron processes Yukawa interactions. interaction transfers these to asymmetry, which in turn is transferred into baryon asymmetry electroweak process. QCD axion dark matter can be simultaneously produced by dynamics same PQ...
A bstract We study the prospects for probing Nnaturalness solution to electroweak hierarchy problem with future gravitational wave observatories. Nnaturalness, in its simplest incarnation, predicts N copies of Standard Model varying Higgs mass parameters. show that certain parameter regions scalar reheaton transfers a substantial energy density sector smallest positive squared while remaining consistent bounds on additional effective relativistic species. In this sector, all six quarks are...
A bstract 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 study cosmological production matter in this model by elucidating dynamics two sources misalignment generated during radiation era. For large masses (above $$ \mathcal{O} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi> </mml:math> (10 − 3 eV)), is produced thermal , which driven...
A component of the dark matter could consist two darkly charged particles with a large mass ratio and massless force carrier. This `atomic' sector behave much like baryonic sector, cooling fragmenting down to stellar-mass or smaller scales. Past studies have shown that cosmic microwave background large-scale structure constraints rule out $\gtrsim 5\%$ in this manner. However, we show that, even percent level fractions, atomic affect some extragalactic galactic observables. We track merger...
Abstract Axions have for some time been considered a plausible candidate dark matter. They can be produced through misalignment, but it has argued that when inflation occurs before Peccei-Quinn transition, appreciable production result from cosmic strings. This the subject of extensive simulations. But there are reasons to skeptical about possible role axion We review and elaborate on these questions, argue parametrically strings already accounted by assumption random misalignment angles....
We show that a thermal relic which decouples from the standard model (SM) plasma while relativistic can be viable dark matter (DM) candidate, if decoupling is followed by period of entropy dilution heats up SM, but not sector. Such diluted hot relics as light keV, accounting for entirety DM, and conflicting with cosmological astrophysical measurements. The requisite achieved via decays heavy state dominates energy budget universe in early dominated era. into SM particles, plasma, dilutes...
We show that a rotating axion field makes transition from matterlike equation of state to kinationlike around the epoch recombination can significantly ameliorate Hubble tension, i.e., discrepancy between determinations present-day expansion rate <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>H</a:mi></a:mrow><a:mrow><a:mn>0</a:mn></a:mrow></a:msub></a:mrow></a:math> observations cosmic microwave background on one hand and type Ia...
We propose a new mechanism for baryogenesis at the 1--200 MeV scale. Enhancement of charge parity ($CP$) violation takes place via interference between oscillations and decays mesinos---bound states scalar quark antiquark their $CP$ conjugates. present in simplified model with four fundamental particles, masses 300 GeV 10 TeV, show that some experimentally allowed parameter space can give observed baryon-to-entropy ratio.
Measurements of the spin stellar mass black holes (BHs) are now possible both through LIGO observations binary BH mergers and for BHs in X-ray systems. The spins as inferred from suggest that on lower end what is expected a ``flat'' distribution spins, while those binaries tend to be large. Superradiance, process can effectively reduce before they merge, could explain observed non self-interacting light boson. In this paper, we use Bayesian analysis infer posterior probability boson fit...
Neutrino masses and the number of light neutrino species can be tested in a variety laboratory experiments also constrained by particle astrophysics precision cosmology. A conflict between these various results could an indication new physics sector. In this paper, we explore possibility for reconciliation otherwise discrepant simple model containing scalar field which produces mass-varying neutrinos. We extend previous work on neutrinos to consider issues clumping, effects additional...
In models with a light scalar field (the ``acceleron'') coupled to neutrinos, neutrino masses depend on density. The resulting system of mass varying neutrinos (MaVaNs) and the acceleron can act as negative pressure fluid is candidate for dark energy [R. Fardon et al. J. Cosmol. Astropart. Phys. 10 (2004) 005]. MaVaNs also allow higher $\mathrm{\ensuremath{\Sigma}}{\mathit{m}}_{\mathit{\ensuremath{\nu}}}$ than terrestrial bounds, giving late forming warm matter. this paper we study effect...
The Standard Model of Particle Physics cannot explain the observed baryon asymmetry Universe. This observation is a clear sign new physics beyond Model. There have been many recent theoretical developments to address this question. Critically, models that generate wide range repercussions for areas and experimental particle physics. white paper provides an overview such with emphasis on testability.
We show that a rotating axion field makes transition from matter-like equation of state to kination-like around the epoch recombination can significantly ameliorate Hubble tension, i.e., discrepancy between determinations present-day expansion rate $H_0$ observations cosmic microwave background on one hand and Type Ia supernovae other. consider specific, UV-complete model such find it relax tension without exacerbating tensions in other cosmological parameters, particular amplitude matter...
The conventional misalignment mechanism for scalar dark matter depends on the initial field value, which governs oscillation amplitude and present-day abundance. We present a by feeble (Planck-suppressed) coupling of to fermion in thermal equilibrium drives towards its high-temperature potential minimum at large values, dynamically generating before oscillations begin. Unlike production, abundance is dictated microphysics not conditions. As an application generic mechanism, we discuss...
This document summarizes the discussions which took place during PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pennsylvania, Sept. 5-7, 2024. Much like non-standard cosmological epochs that were subject of these discussions, format this workshop was also non-standard. Rather than consisting a series talks from participants, with each person presenting their own work, instead organized around free-form discussion blocks, centered...
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 study cosmological production matter in this model by elucidating dynamics two sources misalignment generated during radiation era. For large masses (above order $10^{-3}\,{\rm eV}$), is produced thermal misalignment, which driven towards values as result finite-temperature effective potential. The dominance mass...
We study the prospects for probing Nnaturalness solution to electroweak hierarchy problem with future gravitational wave observatories. Nnaturalness, in its simplest incarnation, predicts $N$ copies of Standard Model varying Higgs mass parameters. show that certain parameter regions scalar reheaton transfers a substantial energy density sector smallest positive squared while remaining consistent bounds on additional effective relativistic species. In this sector, all six quarks are much...
The direct detection of gravitational waves by LIGO has heralded a new era for astronomy and physics. Typically the observed are dominated noise. In this work we use Deep Convolutional Neural Networks (specifically U-Nets) to filter clean signal from noisy data. We present two realizations U-Net filters, Noise2Clean which is trained using same signal, as well Noise2Noise on separate realization signal. find that U-Nets successfully also benchmark performance them detect binary presence or...