A5083294335- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Gamma-ray bursts and supernovae
- CCD and CMOS Imaging Sensors
- Advanced Thermodynamics and Statistical Mechanics
- Relativity and Gravitational Theory
- Computational Physics and Python Applications
- Engineering Applied Research
- Astronomy and Astrophysical Research
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Quantum, superfluid, helium dynamics
Fermi National Accelerator Laboratory
2024-2025
University of Chicago
2024-2025
University of Illinois Chicago
2024
Johns Hopkins University
2020-2023
University of Maryland, College Park
2020-2023
Stony Brook University
2017-2019
State University of New York
2017
We revisit constraints on dark photons with masses below ∼ 100 MeV from the observations of Supernova 1987A. If are produced in sufficient quantity, they reduce amount energy emitted form neutrinos, conflict observations. For first time, we include effects finite temperature and density kinetic-mixing parameter, ϵ, this environment. This causes ϵ to weaken dark-photon mass 15 MeV. large-enough values it is well known that can be reabsorbed within supernova. Since rates reabsorption processes...
A bstract We consider the constraints from Supernova 1987A on particles with small couplings to Standard Model. discuss a model fermion coupled dark photon, various mass relations in sector; millicharged particles; dark-sector fermions inelastic transitions; hadronic QCD axion; and an axion-like particle that couples Model proportional their mass. In cases, we develop new diagnostic for assessing when such is trapped at large mixing angles. Our bounds photon constrain masses ≲ 200 MeV, do...
We examine the theoretical motivations for long-lived particle (LLP) signals at LHC in a comprehensive survey of Standard Model (SM) extensions. LLPs are common prediction wide range theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, represent natural generic possibility physics beyond SM (BSM). In most cases LLP lifetime can be treated free parameter from $\mu$m scale up to Big Bang Nucleosynthesis limit $\sim 10^7$m....
We perform a comprehensive study of cosmological constraints on nonstandard neutrino self-interactions using cosmic microwave background and baryon acoustic oscillation data. consider different scenarios for distinguished by the fraction states allowed to participate in how relativistic energy density, ${N}_{\mathrm{eff}}$, is vary. Specifically, we cases which all self-interact ${N}_{\mathrm{eff}}$ varies; two species free-stream, show alleviates tension with laboratory constraints, while...
Dark matter produced from thermal freeze-out is typically restricted to have masses above roughly 1 MeV. However, if the couplings are small, freeze-in mechanism allows for production of dark down keV masses. We consider coupled a photon that mixes with and photons through an electric or magnetic dipole moment. discuss contributions such particles standard model fermion-antifermion annihilation plasmon decay. also derive constraints on cooling red giant stars horizontal branch stars,...
Dark radiation (DR) is generally predicted in new physics scenarios that address fundamental puzzles of the Standard Model or tensions cosmological data. Cosmological data have sensitivity to constrain not only energy density DR but also whether it interacting. In this paper, we present a systematic study five types interacting (free-streaming, fluid, decoupling, instantaneous and recoupling DR) their impact on observables. We modify Boltzmann hierarchy describe all these under relaxation...
Future gamma-ray experiments, such as the e-ASTROGAM and AMEGO telescopes, can detect Hawking radiation of photons from primordial black holes (PBHs) if they make up a fraction or all dark matter. PBHs analogously also radiate new particles, which is especially interesting these particles are mostly secluded Standard Model (SM) sector, since might therefore be less accessible otherwise. A well-motivated example this type axion-like (ALPs) with tiny coupling to photons. We assume that ALPs...
Abstract The QCD axion and axion-like particles, as leading dark matter candidates, can also have interesting implications for substructures if the Peccei-Quinn symmetry is broken after inflation. In such a scenario, perturbations on small scales will lead to formation of miniclusters at matter-radiation equality, subsequently stars. Such compact objects open new windows indirect searches axions. We compute star mass function based recent minicluster studies Bose simulations. Applying this...
Asteroid-mass primordial black holes (PBHs) can explain the observed dark matter abundance while being consistent with current indirect detection constraints. These PBHs produce gamma-ray signals from Hawking radiation that are within sensitivity of future measurements by AMEGO and e-ASTROGAM experiments. which give rise to such observable have a cosmic origin large curvature fluctuations. There must then be companion, stochastic gravitational wave (GW) background produced same We...
We present the complete history of structure formation in a simple dissipative dark-sector model. The model has only two particles: dark electron, which is subdominant component matter, and photon. Dark-electron perturbations grow from primordial overdensities, become non-linear, form dense galaxies. Bremsstrahlung cooling leads to fragmentation dark-electron halos into clumps that vary size few millions solar masses, depending on particle parameters. In particular, we show asymmetric stars...
We initiate a study of the gravitational-wave signatures phase transition that occurs as Universe's temperature increases during reheating. The such heating are different from those cooling transition, and their detection could allow us to probe In lucky case both transitions were be observed, information about reheating in principle obtained utilizing correlations between two transitions. Frictional effects, leading constant bubble-wall speed one case, will instead behave an...
Recent studies reveal that more than a dozen of white dwarfs displaying near-perfect blackbody spectra in the optical range have been lurking Sloan Digital Sky Survey catalog. We point out that, way analogous to cosmic microwave background, these stars serve as excellent test beds for new physics. Specifically, we show how their observed lack spectral distortions translates into limits on parameter space axions with electromagnetic coupling. The prospects future improvements are also discussed.
Finite temperature effects in the Standard Model tend to restore electroweak symmetry early universe, but new fields coupled higgs field may as well reverse this tendency, leading so-called non-restoration (EW SNR) scenario. Previous works on EW SNR often assume that reversal is due thermal fluctuations of with negative quartic couplings higgs, and they find a large number are required. We observe can be minimally realized if field(s) develop(s) stable condensate. show one complex scalar...
We study the solar emission of light dark sector particles that self-interact strongly enough to self-thermalize. The resulting outflow behaves like a fluid which accelerates under its own thermal pressure highly relativistic bulk velocities in system. Compared ordinary noninteracting scenario, local has at least ∼10^{3} higher number density and correspondingly lower average energy per particle. show how this generic phenomenon arises composed millicharged self-interacting via photon....
We propose a novel baryogenesis scenario where the baryon asymmetry originates directly from hierarchy between two fundamental mass scales: electroweak scale and Planck scale. Our model is based on neutrino-portal Affleck-Dine (AD) mechanism, which generates of AD sector during radiation-dominated era subsequently transfers it to number before phase transition. The observed then natural outcome this scenario. testable as predicts existence Majoron with keV an decay constant. impact relic...
The QCD axion and axion-like particles, as leading dark matter candidates, can also have interesting implications for substructures if the Peccei-Quinn symmetry is broken after inflation. In such a scenario, perturbations on small scales will lead to formation of miniclusters at matter-radiation equality, subsequently stars. Such compact objects open new windows indirect searches axions. We compute star mass function based recent minicluster studies Bose simulations. Applying this function,...
We propose a novel baryogenesis scenario where the baryon asymmetry originates directly from hierarchy between two fundamental mass scales: electroweak scale <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>v</a:mi></a:math> and Planck <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>M</c:mi><c:mi>P</c:mi></c:msub></c:math>, in form of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...
Recent studies reveal that more than a dozen of white dwarfs displaying near-perfect blackbody spectra in the optical range have been lurking Sloan Digital Sky Survey catalog. We point out that, way analogous to Cosmic Microwave Background, these stars serve as excellent testbeds for new physics. Specifically, we show how their observed lack spectral distortions translates into limits on parameter space axions with electromagnetic coupling. The prospects future improvements are also discussed.
We initiate a study of the gravitational-wave signatures phase transition that occurs as Universe's temperature increases during reheating. The such heating are different from those cooling transition, and their detection could allow us to probe In lucky case both transitions were be observed, information about reheating in principle obtained utilizing correlations between two transitions. Frictional effects, leading constant bubble-wall speed one case, will instead behave an...
We study the solar emission of light dark sector particles that self-interact strongly enough to self-thermalize. The resulting outflow behaves like a fluid which accelerates under its own thermal pressure highly relativistic bulk velocities in system. Compared ordinary non-interacting scenario, local has at least $\sim 10^3$ higher number density and correspondingly lower average energy per particle. show how this generic phenomenon arises comprised millicharged self-interacting via photon....
Future gamma-ray experiments, such as the e-ASTROGAM and AMEGO telescopes, can detect Hawking radiation of photons from primordial black holes (PBHs) if they make up a fraction or all dark matter. PBHs analogously also radiate new particles, which is especially interesting these particles are mostly secluded Standard Model (SM) sector, since might therefore be less accessible otherwise. A well-motivated example this type axion-like (ALPs) with tiny coupling to photons. We assume that ALPs...