We consider a new mechanism for enhancing the self-scattering of dark matter without a light mediator or a sub-GeV dark matter. The mechanism relies on the u-channel resonance from a dark matter particle in models with at least two components of dark matter with self-couplings. We develop the Bethe-Salpeter formalism for obtaining the non-perturbative cross section and the Sommerfeld...
Primordial Black Holes (PBH) in the intermediate mass range can be seeds for supermassive black holes and recent LIGO detections of black hole mergers in the mass gap suggest PBH progenitors. I present a novel constraint on the PBH mass fraction spanning PBH masses of 10-10^7 solar masses from thermal equilibrium considerations. A population of PBH in the central region of the dwarf galaxy Leo...
we present a novel mechanism for Sommerfeld effect for dark matter interactions without light mediator. Considering two component dark model with triple interaction, we find one of dark matter leads to an u-channel resonance in dark matter elastic scattering.
We propose a new mechanism to communicate between fermion dark matter and the SM only through the four-form flux. The four-form couplings are responsible for the relaxation of the Higgs mass to the correct value and the initial displacement of the reheating pseudo-scalar field from the minimum. We show that the simultaneous presence of the pseudo-scalar coupling to fermion DM and the...
We explore the impact of neutral-current non-standard neutrino interactions (NSI) on the propagation of atmospheric neutrinos using the future experiments, DUNE and HK as well as the future planned KNO and ORCA neutrino detectors. We study the potential of these experiments to constrain the matter NSI parameters assuming ten years of data taking of atmospheric neutrinos and find the...
Cosmological structures at subgalacticscales are pristine testbeds for dark matter(DM) physics. However, they are too diffuse and dark to be visible in any existing observations. In thiswork,wedevelopformalisms for diffractive lensing and show that itcanbeusedto detect diffuseDM halos with chirping gravitational waves(GWs) from massive binary black holes. Assuming Navarro-Frenk-White profile...
In this talk, we will demonstrate the redistribution of dark matter mass densities in an UV complete model with U(1)_D to Z_4 symmetry.
I will review a recent development of flavor symmetry introducing a modular symmetry.
The recently suggested Festina-Lente (FL) bound provides a lower bound on the masses of
U(1) charged particles in terms of the positive vacuum energy. Since the charged particle masses in the Standard Model (SM) are generated by the Higgs mechanism, the FL bound provides a testbed of consistent Higgs potentials in the current dark energy-dominated universe as well as during inflation. We...
If the strange quark were lighter, QCD phase transition could have been first order. This implies that QCD may have quantum critical points as the Higgs vev v_h is varied from its Standard Model value. We show that inflationary quantum evolution of v_h with the relaxion can drive our universe toward those critical points, realizing the weak scale close to the observed value while explaining...
Primordial black holes are gaining a renewed interest as a source of various phenomena in our early universe, and are regarded to be appealing probes for the curvature perturbation at small scales. These enhanced curvature perturbations also lead to second order gravitational waves, with many ranges of frequencies within reach of future observations. Here I analyze the curvature perturbation...
In the inflationary paradigm, reheating processes have potentially rich phenomenology. First, for observational side, this affects to predictions on cosmological observables. We study effects of reheating on inflationary predictions of models with general non-minimal coupling possessing asymptotically flat potential, including Higgs inflation. We consider wide range of non-minimal coupling in...
Higgs inflation has drawn attention due to the minimal possibility of the Standard Model Higgs playing the role of the inflation field. However, the large non minimal coupling with gravity leads to unitarity violation. In this talk, we consider a class of models dubbed sigma-models, UV completions to Higgs inflation arising from general higher curvature terms beyond Einstein gravity. We...
It is known that the Higgs inflation suffers from unitarity problem due to a large non-minimal coupling of Higgs field to Ricci scalar. Recently, it has been clear that introducing a Ricci square term (R2 term) in the Higgs inflation can solve this problem, and provide its UV completion. This model known as Higgs-R2 inflation perfectly agrees with the CMB observation of the Planck result. In...
We study the phenomenological signatures of the light charged Higgs in Type-I 2HDM. The previous studies rely on its production via the decay of top quark into a light charged Higgs boson and a bottom quark. Over random scanning, we obtain the viable parameter space and suggest more efficient production and decay channels.
We propose a model for the vector-like lepton to explain the small muon mass by a see-saw mechanism, based on lepton-specific two Higgs doublet models with a local $U(1)'$ symmetry. There is no bare muon mass for a nonzero $U(1)'$ charge of the leptophilic Higgs doublet, so the physical muon mass is generated due to the mixing between the vector-like lepton and the muon after the leptophilic...
In 2020, CMS collaboration reported the significance of 3.0$\sigma$ for the Higgs boson decay to dimuon process. We propose that by using quark/gluon tagging of the initial state radiation(ISR) jets, the significance can be considerably enhanced. We exploit the difference in the fraction of quark/gluon ISR jets of gluon-fusion Higgs signal and its background, Drell-Yan. By conducting...
I will talk about the effects of multi-component boosted dark matter in various astrophysical phenomena. Also, its effect to various neutrino experimental and dark matter direct detection experimental results
Various alleged indirect dark matter search signals, such as the 511 keV line from galaxy center or the PAMELA/AMS02 signal, are often challenged by the absence of corresponding signal from dwarf galaxies and/or from the absence of an impact on CMB through delayed recombination. We propose a novel scenario to explain 511 keV signal, that can avoid these bounds based on the decay of dark...
I will discuss a few models that can accommodate flavor anomalies as well as dark matter of the universe.
