195 citations · 1k across the 23 of their papers we have counts for
25 papers
Probing an ultralight QCD axion with electromagnetic quadratic interaction
Hyungjin Kim, Alessandro Lenoci, Gilad Perez +1
The axion-gluon coupling is the defining feature of the QCD axion. This feature induces additional and qualitatively different interactions of the axion with standard model particl…
Gravitational Interaction of Ultralight Dark Matter with Interferometers
Hyungjin Kim
Ultralight dark matter exhibits an order-one density fluctuation over the spatial scale of its wavelength. These fluctuations gravitationally interact with gravitational wave inter…
Adiabatically compressed wave dark matter halo and intermediate-mass ratio inspirals
Hyungjin Kim, Alessandro Lenoci, Isak Stomberg +1
The adiabatic growth of a central massive black hole could compress the surrounding dark matter halo, leading to a steeper profile of the dark matter halo. This phenomenon is calle…
Oscillations of atomic energy levels induced by QCD axion dark matter
Hyungjin Kim, Gilad Perez
Axion-gluon interaction induces quadratic couplings between the axion and the matter fields. We find that, if the axion is an ultralight dark matter field, it induces small oscilla…
Gravitational Focusing of Wave Dark Matter
Hyungjin Kim, Alessandro Lenoci
A massive astrophysical object deforms a local distribution of dark matter, resulting in a local overdensity of dark matter. This phenomenon is often referred to as gravitational f…
Assessing the Fornax globular cluster timing problem in different models of dark matter
Nitsan Bar, Diego Blas, Kfir Blum +1
We investigate what the orbits of globular clusters (GCs) in the Fornax dwarf spheroidal (dSph) galaxy can teach us about dark matter (DM). This problem was recently studied for ul…
A constraint on light primordial black holes from the interstellar medium temperature
Hyungjin Kim
Primordial black holes are a viable dark matter candidate. They decay via Hawking evaporation. Energetic particles from the Hawking radiation interact with interstellar gas, deposi…
Probing the relaxed relaxion and Higgs-portal with S1 & S2
Ranny Budnik, Hyungjin Kim, Oleksii Matsedonskyi +2
We study the recent \XeT excess in context of solar scalar, specifically in the framework of Higgs-portal and the relaxion model. We show that $m_ϕ= 1.9\,\keV$ and $g_{ϕe}=2.4\time…
Probing the Relaxed Relaxion at the Luminosity and Precision Frontiers
Abhishek Banerjee, Hyungjin Kim, Oleksii Matsedonskyi +2
Cosmological relaxation of the electroweak scale is an attractive scenario addressing the gauge hierarchy problem. Its main actor, the relaxion, is a light spin-zero field which dy…
Searching for Earth/Solar Axion Halos
Abhishek Banerjee, Dmitry Budker, Joshua Eby +4
We discuss the sensitivity of the present and near-future axion dark matter experiments to a halo of axions or axion-like particles gravitationally bound to the Earth or the Sun. T…
Searching for a solar relaxion/scalar with XENON1T and LUX
Ranny Budnik, Oz Davidi, Hyungjin Kim +2
We consider liquid xenon dark matter detectors for searching a light scalar particle produced in the solar core, specifically one that couples to electrons. Through its interaction…
Super heavy thermal dark matter
Hyungjin Kim, Eric Kuflik
We propose a mechanism of elementary thermal dark matter with mass up to GeV, within a standard cosmological history, whose relic abundance is determined solely by its in…
Relaxion Stars and their detection via Atomic Physics
Abhishek Banerjee, Dmitry Budker, Joshua Eby +2
The cosmological relaxion can address the hierarchy problem, while its coherent oscillations can constitute dark matter in the present universe. We consider the possibility that th…
Coherent relaxion dark matter
Abhishek Banerjee, Hyungjin Kim, Gilad Perez
We show that relaxion, that addresses the hierarchy problem, can account for the observed dark matter (DM) relic density. The setup is similar to the case of axion DM models topped…
Self-heating of Strongly Interacting Massive Particles
Ayuki Kamada, Hee Jung Kim, Hyungjin Kim
It was recently pointed out that semi-annihilating dark matter (DM) may experience a novel temperature evolution dubbed as self-heating. Exothermic semi-annihilation converts the D…
Late-time magnetogenesis driven by ALP dark matter and dark photon
Kiwoon Choi, Hyungjin Kim, Toyokazu Sekiguchi
We propose a mechanism generating primordial magnetic fields after the annihilations. Our mechanism involves an ultra-light axion-like particle (ALP) which constitutes the…
Self-heating dark matter via semi-annihilation
Ayuki Kamada, Hee Jung Kim, Hyungjin Kim +1
The freeze-out of dark matter (DM) depends on the evolution of the DM temperature. The DM temperature does not have to follow the standard model one, when the elastic scattering is…
Axion-like particle assisted strongly interacting massive particle
Ayuki Kamada, Hyungjin Kim, Toyokazu Sekiguchi
We propose a new realization of strongly interacting massive particles (SIMP) as self-interacting dark matter, where SIMPs couple to the Standard Model sector through an axion-like…
Pulsar Timing Constraints on Physics Beyond the Standard Model
Niayesh Afshordi, Hyungjin Kim, Elliot Nelson
We argue that massive quantum fields source low-frequency long-wavelength metric fluctuations through the quantum fluctuations of their stress-energy, given reasonable assumptions…
Dynamics of the cosmological relaxation after reheating
Kiwoon Choi, Hyungjin Kim, Toyokazu Sekiguchi
We examine if the cosmological relaxation mechanism, which was proposed recently as a new solution to the hierarchy problem, can be compatible with high reheating temperature well…
A map of the non-thermal WIMP
Hyungjin Kim, Jeong-Pyong Hong, Chang Sub Shin
We study the effect of the elastic scattering on the non-thermal WIMP, which is produced by direct decay of heavy particles at the end of reheating. The non-thermal WIMP becomes im…
750 GeV diphoton resonance and electric dipole moments
Kiwoon Choi, Sang Hui Im, Hyungjin Kim +1
We examine the implication of the recently observed 750 GeV diphoton excess for the electric dipole moments of the neutron and electron. If the excess is due to a spin zero resonan…
Aligned natural inflation with modulations
Kiwoon Choi, Hyungjin Kim
The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by su…
Primordial perturbations from dilaton-induced gauge fields
Kiwoon Choi, Ki-Young Choi, Hyungjin Kim +1
We study the primordial scalar and tensor perturbations in inflation scenario involving a spectator dilaton field. In our setup, the rolling spectator dilaton causes a tachyonic in…