A5047914486- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Neutrino Physics Research
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Stochastic processes and financial applications
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Scientific Research and Discoveries
- Advanced Optical Sensing Technologies
- Meteorological Phenomena and Simulations
- Economic Theory and Policy
- Atomic and Subatomic Physics Research
- Superconducting and THz Device Technology
- CCD and CMOS Imaging Sensors
- Cryospheric studies and observations
University of Chinese Academy of Sciences
2022-2024
International Centre for Theoretical Physics Asia-Pacific
2022-2024
Institute for Basic Science
2014-2022
Nagoya University
2012-2022
Yunnan University
2020
Tsinghua University
2020
University of Michigan–Ann Arbor
2009-2012
University of Minnesota
2006-2009
Twin Cities Orthopedics
2009
Aoyama Gakuin University
2009
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes physics inflation. focus on prospects for using CMB to differentiate various inflationary mechanisms. In particular, a detection primordial B‐mode would demonstrate that inflation occurred at very high energy scale, and inflaton traversed super‐Planckian distance in field space. explain how such or constraint illuminate aspects Planck scale. Moreover, can constrain scale‐dependence...
We study the conditions for adiabatic resonant conversion of cold dark matter (CDM) axions into photons in astrophysically sourced strong magnetic fields such as those neutron star magnetosphere. demonstrate possibility that forthcoming radio telescopes SKA (Square Kilometre Array) can probe photon signals from CDM axions.
We demonstrate that elastic scattering between dark matter (DM) and baryons can affect the thermal evolution of intergalactic medium at early epochs discuss observational consequences. show that, due to interaction DM baryons, baryon temperature is cooled after decoupling from CMB temperature. illustrate our findings by calculating 21 cm power spectrum in coexistence with a velocity-dependent cross section. For instance, for mass 10 GeV, brightness angular be suppressed factor 2 within...
The presence of dark matter overdensities surrounding a black hole can influence the evolution binary system. gravitational wave signals emitted by offer promising means to probe environments near hole. dense region lead dephasing waveforms, which be detected upcoming experiments such as Laser Interferometer Space Antenna (LISA). density profile around vary for different models. Our study specifically investigates impact ultralight self-interacting scalar (SIDM) on binaries. A distinctive...
The hot dense environment of the early universe is known to have produced large numbers baryons, photons, and neutrinos. These extreme conditions may also other long-lived species, including new light particles (such as axions or sterile neutrinos) gravitational waves. effects any such relics can be observed through their unique imprint in cosmic microwave background (CMB), large-scale structure, primordial element abundances, are important determining initial universe. We argue that future...
The kinetic decoupling of dark matter (DM) from the primordial plasma sets size first and smallest DM halos. Studies have hitherto mostly neglected interactions between quarks in plasma. Here we illustrate their importance using two frameworks: a version minimal supersymmetric standard model an effective field theory with DM-quark interaction operators. We connect particle physics astrophysics obtaining bounds on halo collider data direct search experiments. In Minimal Supersymmetric...
It was recently proposed that a field theory cannot be consistent with quantum gravity if it allows mode shorter than the Planck length to exit Hubble horizon. This is called Trans-Planckian Censorship Conjecture (TCC). We discuss implications of TCC on possible shape inflaton potential in single-field slow-roll inflation. point out (1) there generically an initial condition which total e-folding number Ntotal doubled or more compared e-folds necessary for cosmic microwave background...
We propose a new constraint on millicharged dark matter from considerations galaxy clusters. The charged moves under the influence of randomly oriented magnetic fields in clusters, and corresponding density profile can significantly differ concordance CDM predictions which are well supported cluster observations. With typical amplitude $B=\mathcal O(1)\,μ$G velocity $v=\mathcal O(100)\,$km/sec at radius $R\simeq 1\,$Mpc, we claim that charge $εe$ ($e$ is elementary charge) with mass $m$...
We generalize the local model of primordial non-Gaussianity by promoting parameter fNL to a general scale-dependent functionfNL(k). calculate resulting bispectrum and effect on bias dark matter halos, thus extent which fNL(k) can be measured from large-scale structure observations. By calculating principal components fNL(k), we identify scales where this form is best constrained estimate overlap with previously studied equilateral non-Gaussian models.
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 consider the dark-matter (DM) scenarios consisting of mixture weakly interacting massive particles (WIMPs) and primordial black holes (PBHs) study what fraction total DM can be PBHs. In such scenarios, PBHs accrete WIMPs consequently enhance heating ionization in intergalactic medium due to WIMP annihilations. demonstrate that CMB data give stringent bounds on allowed PBH which are comparable or even tighter than those from gamma-ray depending masses. For instance, Markov-chain Monte...
Through a principal component analysis, we study how accurately cosmic microwave background observables can constrain inflaton potentials in model-independent manner. We apply the general slow-roll approximation our analysis where allow, contrast to standard approximation, possibility of variations ${V}^{\ensuremath{'}\ensuremath{'}}(\ensuremath{\phi})$ and take into account fact that horizon crossing is not an instantaneous event. Our provides set modes be used fitting observables. find...
To illustrate the complementarity of linear collider and astrophysics bounds on light (MeV-scale mass) dark matter (DM), we study constraints magnetic dipole DM from DM-electron interactions at proposed International Linear Collider (ILC) in supernova (SN) 1987A. We particular focus ${e}^{+}{e}^{\ensuremath{-}}$ annihilation, which is common process for producing pairs both ILC SN. estimate moment monophoton signals also energy loss rate due to freely streaming produced The SN can be more...
Abstract If dark matter is made of QCD axions, its abundance determined by the vacuum expectation value acquired axion field during inflation. The usually assumed to follow equilibrium distribution arising from quantum diffusion This leads so-called stochastic window under which can make up all matter. It characterised 10 10.4 GeV ≤ f 17.2 and H end > -2.2 GeV, where decay constant Hubble expansion rate at However, in realistic inflationary potentials, we show that never reaches because...
We study the decay of inflaton in no-scale supergravity and show that due to gravitational interactions through effects is highly suppressed relative case minimal or models with a generic Kahler potential. also gravitinos suppressed. demonstrate sufficient reheating are possible introduction non-trivial gauge kinetic term. This channel may be dominant supergravity, yet yields re-heating temperature which low enough avoid gravitino problem while high for Big Bang Nucleosynthesis baryogenesis.
Even though chaotic inflation is one of the most popular models for its simple dynamics and compelling resolutions to initial condition problems, realization in supergravity has been considered a challenging task. We discuss how dominated by $D$-term can be induced supergravity, which would give new perspective on model building supergravity.
We forecast combined future constraints from the cosmic microwave background and large-scale structure on models of primordial non-Gaussianity. study generalized local model non-Gaussianity, where parameter f_NL is promoted to a function scale, present principal component analysis applicable an arbitrary form f_NL(k). emphasize complementarity between CMB LSS by using Planck, DES BigBOSS surveys as examples, power-law f_NL(k) model, introduce figure merit for measurements scale-dependent
We investigate the effects of a magnetic dipole moment asymmetric dark matter (DM) in evolution Sun. The interaction can lead to sizable DM scattering cross section even for light DM, and large number density find that solar model precision tests, using as diagnostic sound speed profile obtained from helioseismology data, exclude dipolar particles with mass larger than 4.3 GeV 1.6 × 10−17 e cm.
We study the kinetic decoupling of light (lesssim 10 GeV) magnetic dipole dark matter (DM). find that present bounds from collider, direct DM searches, and structure formation allow to remain in thermal equilibrium with early universe plasma until as late electron-positron annihilation epoch. This leads a minimal mass for earliest protohalos thousands solar masses, contrast conventional weak scale scenario where they are order 10^{-6} masses.
The ultra-light scalar fields can arise ubiquitously, for instance, as a result of the spontaneous breaking an approximate symmetry such axion and more generally axion-like particles. In addition to particle physics motivations, these particles also play major role in cosmology by contributing dark matter abundance affecting structure formation at sub-Mpc scales. this paper, we propose use 21cm forest observations probe nature matter. much smaller scales than Lyman-$\alpha$ forest, that is,...
We study the allowed primordial black hole (PBH) dark matter abundance in mixed scenarios consisting of PBHs and self-annihilating weakly interacting massive particles (WIMPs) with a velocity dependent annihilation cross section. first briefly illustrate how WIMP halo profile changes for suppressed p-wave scenarios, compared familiar s-wave then discuss PBH mass upper bound on abundance. The WIMPs can accrete onto to form an ultracompact minihalo spiky density profile. Such spike is...
We discuss a D-term inflation scenario where right-handed sneutrino can be an inflaton field leading to viable and leptogenesis, with minimal form of K\"ahler potential. The decay nonthermally create large enough lepton asymmetry. Its entropy production is also big ameliorate the gravitino problem caused by too high reheating temperature from symmetry breaking field.
Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, abundance is sensitive to any non-Gaussianity primordial density field. It therefore possible that non-Gaussian initial conditions might misinterpreted as sign energy or at least degrade expected constraints on parameters. To address this issue, we perform likelihood analysis an ideal survey similar in size and depth upcoming South Pole Telescope/Dark Energy Survey (SPT-DES). We analyze model which strength...