A5088100005- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Astronomy and Astrophysical Research
- Neutrino Physics Research
- Engineering Technology and Methodologies
- Dental materials and restorations
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Differential Geometry Research
- Advanced machining processes and optimization
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
Kanazawa University
2020-2023
Max Planck Institute for Physics
2018-2020
Deutsches Elektronen-Synchrotron DESY
2016-2018
Max Planck Society
2018
Tokyo Institute of Technology
2013-2016
European Organization for Nuclear Research
2016
Kyoto University
2015
University of Bonn
2015
The University of Tokyo
2010-2013
Niigata University
2010
The cosmological scenario where the Peccei-Quinn symmetry is broken after inflation investigated. In this scenario, topological defects such as strings and domain walls produce a large number of axions, which contribute to cold dark matter universe. previous estimations abundance are updated refined based on field-theoretic simulations with improved grid sizes. possible uncertainties originated in numerical calculations also discussed. It found that axions can be responsible for mass range...
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....
In this paper, we revisit the estimation of spectrum primordial gravitational waves originated from inflation, particularly focusing on effect thermodynamics in Standard Model particle physics. By collecting recent results perturbative and non-perturbative analysis thermodynamic quantities Model, obtain effective degrees freedom including corrections due to non-trivial interaction properties particles for a wide temperature interval. The impact such as well damping free-streaming is...
We analyze the spectrum of axions radiated from collapse domain walls, which have received less attention in literature. The evolution topological defects related to axion models is investigated by performing field-theoretic lattice simulations. simulate whole process defects, including formation global strings, and annihilation due tension walls. has a peak at low frequency, implies that produced walls are not highly relativistic. revisit relic abundance cold dark matter find contribution...
There are a number of observational hints from astrophysics which point to the existence stellar energy losses beyond ones accounted for by neutrino emission. These excessive may be explained new sub-keV mass pseudoscalar Nambu-Goldstone boson with tiny couplings photons, electrons, and nucleons. An attractive possibility is identify this particle axion—the hypothetical pseudo predicted Peccei-Quinn solution strong CP problem. We explore in terms DFSZ-type axion KSVZ-type axion/majoron,...
We revisit the production of gravitational waves from unstable domain walls analyzing their spectrum by use field theoretic lattice simulations with grid size 10243, which is larger than previous study. have recognized that there exists an error in code used study, and correction leads to suppression at high frequencies. The peak located scale corresponding Hubble radius time decay walls, its amplitude consistent naive estimation based on quadrupole formula. Using numerical results,...
We review the physics potential of a next generation search for solar axions: International Axion Observatory (IAXO) . Endowed with sensitivity to discover axion-like particles (ALPs) coupling photons as small gaγ∼ 10−12 GeV−1, or electrons gae∼10−13, IAXO has find QCD axion in 1 meV∼1 eV mass range where it solves strong CP problem, can account cold dark matter Universe and be responsible anomalous cooling observed number stellar systems. At same time, will have enough detect lower axions...
We consider extensions of the Standard Model in which a spontaneously broken global chiral Peccei-Quinn (PQ) symmetry arises as an accidental exact $Z_N$ symmetry. For $N = 9$ or $10$, this can protect accion - Nambu-Goldstone boson arising from spontaneous breaking PQ against semi-classical gravity effects, thus suppressing gravitational corrections to effective potential, while it at same time provide for small explicit term needed make models with domain wall number $N_{\rm DW}>1$, such...
Abstract Cold dark matter axions produced in the post-inflationary Peccei-Quinn symmetry breaking scenario serve as clear targets for their experimental detection, since it is principle possible to give a sharp prediction mass once we understand precisely how they are from decay of global cosmic strings early Universe. In this paper, perform dedicated analysis spectrum radiated based on large scale numerical simulations cosmological evolution field static lattice. Making full use massively...
We investigate the cosmological constraints on axion models where domain wall number is greater than one. In these models, multiple walls attached to strings are formed, and they survive for a long time. Their annihilation occurs due effects of explicit symmetry breaking term which might be raised by Planck-scale physics. perform three-dimensional lattice simulations compute spectra axions gravitational waves produced long-lived walls. Using numerical results, we estimated relic density...
In this paper, following the previous study, we evaluate spectrum of gravitational wave background generated by domain walls which are produced if some discrete symmetry is spontaneously broken in early universe. We apply two different methods to calculate spectrum: One directly from numerical simulations, and another it indirectly estimating unequal time anisotropic stress power scalar field. Both analysises indicate that slope changes at characteristic frequencies corresponding Hubble...
The axion emerges in extensions of the Standard Model that explain absence CP violation strong interactions. Simultaneously, it can provide naturally cold dark matter our universe. Several searches for axions and axion-like particles (ALPs) have constrained corresponding parameter space over last decades but no unambiguous hints their existence been found. mass range below 1 meV remains highly attractive a well motivated region axions. In this White Paper we present description new...
A weakly interacting massive particle (WIMP) is a leading candidate of the dark matter. The WIMP matter abundance determined by freeze-out mechanism. Once we know property such as mass and interaction, can predict abundance. There are, however, several uncertainties in estimation In this work, focus on effect from Standard Model thermodynamics. We revisit its uncertainty due to equation state (EOS) Model. adopt up-to-date estimate EOS early Universe find nearly 10% difference 1–1000 GeV...
The post-inflationary Peccei-Quinn (PQ) symmetry breaking scenario provides a unique opportunity to pinpoint the QCD axion dark matter mass, which is crucial input for laboratory experiments that are designed probing specific mass ranges. Predicting their requires precise knowledge of how axions produced from decay topological defects in early Universe inevitably formed. In this contribution, we present recent results on analysis spectrum radiated global strings based large scale numerical...
We study the cosmological evolution of domain walls bounded by strings which arise naturally in axion models. If we introduce a bias potential, become metastable and finally disappear. perform two dimensional lattice simulations wall networks estimate decay rate walls. By using numerical results, give constraint for parameter Peccei-Quinn scale. also discuss possibility to probe models direct detection gravitational waves produced
In this paper we analyze the spectrum of primordial gravitational waves (GWs) predicted in Standard Model*Axion*Seesaw*Higgs portal inflation (SMASH) model, which was proposed as a minimal extension Model that addresses five fundamental problems particle physics and cosmology (inflation, baryon asymmetry, neutrino masses, strong CP problem, dark matter) one stroke. The SMASH model has unique prediction for critical temperature second order Peccei-Quinn (PQ) phase transition Tc ∼ 108 GeV up...
The next-to-minimal supersymmetric standard model predicts the formation of domain walls due to spontaneous breaking discrete Z3-symmetry at electroweak phase transition, and they collapse before epoch big bang nucleosynthesis if there exists a small bias term in potential which explicitly breaks symmetry. Signatures gravitational waves produced from these unstable are estimated their parameter dependence is investigated. It shown that amplitude becomes generically large decoupling limit,...
We discuss the possibility that dark matter axions form a Bose-Einstein condensate (BEC) due to gravitational self interactions. The formation of BEC occurs in condensed regime, where transition rate between different momentum states is large compared energy exchanged transition. time evolution quantum state occupation number regime derived based on in-in formalism. recover expression for thermalization interaction axion field, which was obtained other literature. It also found leading order...
Received 22 August 2016DOI:https://doi.org/10.1103/PhysRevD.94.049908© 2016 American Physical Society
We study the production of gravitational waves from cosmic domain walls created during phase transition in early universe. investigate process formation and evolution by running three dimensional lattice simulations. If we introduce an approximate discrete symmetry, become metastable finally disappear. calculate spectrum produced collapsing walls. Extrapolating numerical results, find signal whose energy scale is around 10^10-10^12GeV will be observable next generation wave interferometers.
The properties of axion miniclusters and the voids between them can have very strong implications for discovery axions dark matter Universe. These be strongly affected by dynamics in early Universe, such as string network non-linear around QCD phase transition. Recently, improvements numerical simulation techniques allowed us to calculate field from strings effects using different methods: directly with low-tension but high resolution, effective high-tension strings, or indirectly...
We investigate the structure of gravitational self-interactions coherently oscillating axions in general relativistic framework. A generic action for a massive scalar field Friedmann-Robertson-Walker background is first introduced based on effective theory approach to cosmological perturbations. Using obtained setup, we evaluate interaction field, i.e. quartic interactions mediated by metric Applying results system dark matter axions, estimate their self-interaction rate and discuss its...