Studies of the magnetic fields in our universe provide an excellent opportunity to confront monopoles with astrophysical observations. I will discuss two projects along this line: (1) New Parker-type bounds on the monopole flux in light of the modern understanding of cosmological magnetic fields, including galactic, intergalactic, and primordial fields. I will also present constraints on...
We present a novel mechanism for the formation of topologically stable monopoles with two unit of Dirac magnetic charges from the decay of metastable string network in an SO(10) GUT. Superheavy monopoles (masses ~ 1015 – 1017 GeV) can be produced with an observable flux from a string network with the dimensionless tension Gμ ~ 10-9-10-5 (μ is the string tension and G the Newton’s constant) in...
We perform global fits of the Higgs boson couplings to the full Higgs datasets collected at the LHC with the integrated luminosities per experiment of approximately 5/fb at 7 TeV, 20/fb at 8 TeV, and up to 139/fb at 13 TeV. Our combined analysis based on the experimental signal strengths used in this work and the theoretical ones elaborated for our analysis reliably reproduce the results in...
I will discuss the halo-independent bounds on the WIMP-nucleon couplings of the non-relativistic effective Hamiltonian that drives the scattering process off nuclei of a WIMP of spin 1/2 combining direct detection experiments and neutrino telescopes data in order to cover the full WIMP incoming speed range.
In the elastic interactions, for most of the couplings the degree of relaxation of...
I will discuss about theoretical and phenomenological aspects of one-point correlators of conserved and non-conserved charges in QCD
We consider the axion-mediated scattering processes between dark matter (DM) and nucleus. The substantial contributions are made via the CP-odd gluonic current which induces the spin-dependent process. Since the QCD axion is too feebly coupled to the visible particles, non-QCD axions are necessary for the current DM experiments to accomplish the ample sensitivity. In the case of...
We show that the process of non-instantaneous reheating during the post-inflationary period can have a sizable impact on the charged lepton Yukawa equilibration temperature in the early Universe. This suggests relooking the effects of lepton flavors in the leptogenesis scenario where the production and decay of right-handed neutrinos take place within this prolonged era of reheating. We find...
I will discuss the stochastic gravitational waves (GWs) spectrum, resulting from the emission of gravitons through bremsstrahlung, in the decay of particles produced by Hawking radiation. Although particle decays inevitably entail the emission of graviton due to bremsstrahlung, the associated decay width is notably suppressed due to the Planck scale suppression in the coupling of matter fields...
This talk explores second-order gravitational waves (GWs) originating from
scalar-tensor perturbation interactions during the radiation-dominated phase
of the Universe. We investigate the unique features and detectability of
these GWs compared to the scalar-induced ones. Unlike scalar-scalar
induced GWs, scalar-tensor induced GWs lack resonances or logarithmic
running in the low frequency...
We show that the merger rate of primordial black hole (PBH) binaries in the dark matter (DM) spike can greatly change the merger rate history of PBHs in late universe, since the high DM density in DM spike enhances the merger rate of PBHs, especially for the DM profile index gamma, larger than 1.7. This PBH merger rate from DM spike causes a bump structure in its merger rate history at...
I will introduce the minimal cosmological standard model(MCSM) which we proposed recently as a minimal BSM scenario to address various theoretical/phenomenological/cosmological big puzzles in a simple framework.
Cosmological perturbations generated during inflation are the seeds of the inhomogeneity and anisotropy of our universe. In contrast with the usual perturbation theory explaining these perturbations at large scale well, the stochastic formalism is an effective theory of long-wavelength modes that incorporates probabilistic noise from short-wavelength modes as they exit the horizon. This is...
We explain the physics potential of the present SND@LHC experiment and the future SHiP experiment.
We calculate the one-loop corrections due to the curvature perturbation to the tensor power spectrum during inflation. This requires the quartic order action of both scalar and tensor perturbations.
Supported by observational evidence indicating that cosmological scalar perturbations were nearly Gaussian at the beginning of the universe, it is anticipated that the origin of these perturbations is quantum fluctuations. Consequently, cosmic inflation provides a valuable setting for testing the quantum nature with/of gravity. Quantumness is characterized by features such as quantum...
Spherical collapse is assumed in most of the works on PBH formation from
the primordial curvature perturbation. According to the peak theory[1],
sufficiently high peaks of a Gaussian random scalar field statistically have
spherical symmetric shapes in the homogeneous and isotropic universe,
which guarantees the above assumption. However, the PBH formation is
related to highly non-linear...
Gravitational lensing of gravitational wave(GW), or GW lensing for short, is a unique tool that enables us to explore the ultra-small-scale matter distribution in our universe. One of the distinctive features of GW lensing is its wave nature, which arises from the long wavelength of typical GW sources. Fully utilizing the wave nature, GW lensing can probe O(0.1) ~O(10) parsec scales matter...
The motivation of this talk is to discuss how to probe gravity theories using the quasinormal modes (QNMs) in the ringdown phase of binary black hole mergers.
In this talk, the speaker will introduce the parametrized black hole quasinormal ringdown formalism, a robust framework for analyzing the QNMs in systems resembling GR, with a focus on higher overtones. These overtones have been shown...
We explore the sensitivity of the radio telescope to light dark matter, such as sub-GeV dark matter and axion-like particles. We will also discuss the complementarity of these forthcoming radio signal bounds with current experimental constraints from other investigations, highlighting the synergistic potential of multi-messenger astronomy in understanding dark matter.
Plenty of efforts have been made to explore the black string and its instability, but the fate of the black strings with fewer extra dimensions is still inconclusive. Now starting from the 5D uniform black string, we show that the EHT observations of M87 and SgrA can not only rule out the black string with an infinite extra dimension, but also constrain the length of a compact extra...
We consider the phenomenology of the Higgs bosons in the hidden sector model mediated by an additional SU(2) scalar doublet. With the mediator scalar doublet, the Higgs sector of the model is extended to be that of the two Higgs doublet model of type I. The mediator scalar doublet is connected to the hidden sector with the hidden U(1)𝑋 gauge charge. Then the U(1)𝑋 gauge symmetry is...
Oscillons are long-lived localized spherical solitons of real scalar field with potential flatter than quadratic. They are considered to be formed at the end of inflation and important in the early universe. Their lifetime can be greatly effected by the coupling of inflaton field to other fields. We consider an oscillon coupled with another real scalar field and investigate the effect on the...
Due to the extraordinarily high energy scales inherent to inflation, it naturally functions as a cosmological collider to probe physics at otherwise inaccessible energy regimes, and the information are encoded in cosmological correlators. After many efforts in recent years, the analytical structure of the correlators associated with single massive spinning field exchange is well understood....
