A5025405218- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Black Holes and Theoretical Physics
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Quantum Chromodynamics and Particle Interactions
- Astronomy and Astrophysical Research
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Atomic and Subatomic Physics Research
- Computational Physics and Python Applications
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Advanced Topics in Algebra
- Adaptive optics and wavefront sensing
- Algebraic structures and combinatorial models
- Relativity and Gravitational Theory
- Stellar, planetary, and galactic studies
- Atmospheric Ozone and Climate
Kavli Institute for the Physics and Mathematics of the Universe
2016-2025
University of California, Los Angeles
2016-2025
The University of Tokyo
2015-2024
European Organization for Nuclear Research
1997-2023
Instituto Nacional de Técnica Aeroespacial
2023
UCLA Health
1999-2022
Centre de Recherche en Astronomie Astrophysique et Géophysique
2018
Institut National de Physique Nucléaire et de Physique des Particules
2018
Université Paris-Sud
2018
Centre National de la Recherche Scientifique
2018
Although the origin of matter-antimatter asymmetry remains unknown, continuing advances in theory and improved experimental limits have ruled out some scenarios for baryogenesis, example, sphaleron baryogenesis at electroweak phase transition Standard Model. At same time, success cosmological inflation prospects discovering supersymmetry Large Hadron Collider put other models sharper focus. We review current state our understanding with emphasis on those that we consider most plausible.
This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and latest astrophysical data.
We identify the range of parameters for which sterile neutrinos can simultaneously explain cosmological dark matter and observed velocities pulsars. To satisfy all bounds, relic must be produced sufficiently cold. This is possible in a class models with gauge-singlet Higgs boson coupled to neutrinos. Sterile detected by x-ray telescopes. The presence singlet sector tested at CERN Large Hadron Collider.
Sterile neutrino with mass of several keV can be the cosmological dark matter, explain observed velocities pulsars, and play an important role in formation first stars. We describe production sterile neutrinos a model extended Higgs sector, which Majorana term is generated by vacuum expectation value gauge-singlet boson. In this relic abundance does not necessarily depend on their mixing angles, free-streaming length much smaller than case warm matter produced oscillations, and, therefore,...
Primordial black hole (PBH) formation is a more generic phenomenon than was once thought. The dynamics of scalar field in inflationary universe can produce PBHs under mild assumptions regarding the potential. In early universe, light fields develop large expectation values during inflation and subsequently relax to minimum effective potential at later time. During relaxation process, an initially homogeneous condensate fragment into lumps via instability similar gravitational (Jeans)...
The scalar potential of the MSSM may have local and global minima characterized by non-zero expectation values charged colored bosons. Even if true vacuum is not color charge conserving, early Universe likely to occupy minimum in which only neutral Higgs fields vev's. stability this false with respect quantum tunneling imposes important constraints on parameters. We analyze these using some novel methods for calculating decay rate. Some regions parameter space are ruled out because lifetime...
A monochromatic line in the cosmic neutrino spectrum would be a smoking gun signature of dark matter. It is intriguing that IceCube experiment has recently reported two PeV events with energies may equal up to experimental uncertainties, and which have probability being background fluctuation estimated less than percent. Here we explore prospects for these first indication signal from While measurable annihilation signatures seem impossible at such energies, discuss matter quantum numbers,...
Intergalactic magnetic fields (IGMFs) can cause the appearance of halos around gamma-ray images distant objects because an electromagnetic cascade initiated by a high-energy interaction with photon background is broadened deflections. We report evidence such in stacked 170 brightest active galactic nuclei (AGNs) 11 month source catalog Fermi Gamma-Ray Space Telescope. Excess over point-spread function surface brightness profile statistically significant at 3.5σ (99.95% confidence level), for...
We propose a novel scenario to produce abundant primordial black holes (PBHs) in new inflation which is second phase of double the supergravity framework. In our model, some preinflation before assumed and it would be responsible for curvature perturbations on cosmic microwave background scale, while produces only small scale perturbations. Our model has linear, quadratic, cubic terms its potential PBH production corresponds with flat inflection point. The linear term can interpreted come...
We show that fragmentation of the inflaton into long-lived spatially localized oscillon configurations can lead to copious production black holes. In a single-field inflation model primordial holes sublunar mass form, and they account for all dark matter. also explore possibility solar-mass holes, particularly relevant gravitational wave astronomy, are produced from same mechanism.
Secondary photons and neutrinos produced in the interactions of cosmic ray protons emitted by distant active galactic nuclei (AGN) with photon background along line sight can reveal a wealth new information about intergalactic magnetic fields, extragalactic light, acceleration mechanisms rays. The secondary may have already been observed gamma-ray telescopes. We show that improve prospects discovering blazars IceCube, we discuss ramifications for backgrounds, AGN models.
Supersymmetric extensions of the standard model generically predict that in early Universe a scalar condensate can form and fragment into Q balls before decaying. If dominate energy density for some period time, relatively large fluctuations their number lead to formation primordial black holes (PBH). Other fields, unrelated supersymmetry, play similar role. For general charged field, this robust mechanism generate over entire mass range allowed by observational constraints, with sufficient...
Active galactic nuclei (AGN) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary produced along the line of sight interactions cosmic-ray protons with background photons. This explains surprisingly low attenuation for blazars, because production occurs, on average, much closer to Earth than distance source. Thus spectrum in TeV range does not depend intrinsic spectrum, while it depends output source We...
Primordial black holes (PBHs) are a viable candidate for dark matter if the PBH masses in currently unconstrained "sublunar" mass range. We revisit possibility that PBHs were produced by nucleation of false vacuum bubbles during inflation. show this scenario can produce population simultaneously accounts all matter, explains event Subaru Hyper Suprime-Cam (HSC) data, and contains both heavy as observed LIGO very seeds supermassive holes. demonstrate with numerical studies future observations...
We set a new upper limit on the abundance of primordial black holes (PBH) based existing X-ray data. PBH interactions with interstellar medium should result in significant fluxes photons, which would contribute to observed number density compact objects galaxies. The data constrain mass range from few M⊙ 2× 107 M⊙. needed account for origin detected by LIGO is marginally allowed.