An axion can couple to photons in a parity-violating manner. Through this coupling, variations in the axion field induce a rotation of the linear polarization plane of photons, i.e., cosmic birefringence. Recently, a hint of isotropic cosmic birefringence has been reported in the EB cross-correlation of the CMB data. In this talk, I will explain the relation between the EB signal and cosmic...
We study the kinetic mixing between the cosmic microwave background (CMB) photon and the birefringent dark photon as a source of cosmic birefringence. We show that indeed the birefringence of the dark photon propagates to the CMB photon, but the resulting birefringence may not be uniform over the sky. Moreover, our investigation sheds light on the essential role played by kinetic mixing in the...
I will discuss the impact of the polarization angle miscalibration on measurements of cosmic isotropic birefringence derived from multi-frequency data of cosmic microwave background polarization experiments.
When coupled to electromagnetism via a Chern-Simons interaction, axion-like particles produce a rotation of the plane of linear polarization of photons known as cosmic birefringence (CB). Recent measurements obtained from WMAP and Planck cosmic microwave background (CMB) polarization data hint at the existence of an isotropic CB angle of β≈0.3º. Although still under scrutiny for their...
The fundamental nature of dark matter (DM) so far eludes direct detection experiments, but it has left its imprint in the cosmic microwave background (CMB) and large-scale structure (LSS) of the Universe. I will present new results demonstrating how the discrepancy in the amplitude of density fluctuations between CMB and LSS observations (galaxy clustering, weak lensing and Lyman-alpha forest)...
The upcoming generation of cosmic microwave background experiments offers an exciting opportunity to study models of exotic dark matter and their clustering behaviors through studies of gravitational lensing at small angular scales (<~ arcmin). I will present the development and application of a novel estimator for quantifying the statistics of the cosmic background lensing field, and show...
Ultralight scalar boson of particle mass 10-22 ~ 10-21 eV/c2, motivated by Axion-Like Particle (ALP), is one of the dark matter candidates, so called UltraLight Dark Matter (ULDM). Its de'Brogile wavelength of ~O(1kpc) gives rise to the wave nature in our universe, governed by Schrodinger-Poisson Equation (SPE) in the nonrelativistic limit.
We focus on two...
The frequency spectrum of the cosmic microwave background (CMB) remains a valuable and nearly untapped resource of cosmological data. By searching for departures from a perfect blackbody, it is possible to sensitively constrain the thermal history of the universe back to redshifts roughly three orders of magnitude higher than with CMB temperature anisotropies. In this talk, I will review the...
The accretion of dark matter (DM) into astrophysical black holes slowly increases their mass. The rate of this mass accretion depends on the DM model and the model parameters. If this mass accretion effect can be measured accurately enough, it is possible to rule out some DM models, and, with the sufficient technology and the help of other DM constraints, possibly confirm one model. We propose...
We review the expected impact of high precision measurements of the B-Mode of CMB anisotropies onto the tensions in the Cosmological Concordance Model. We focus on the reconstruction of the expansion history through cosmological gravitational lensing of the CMB, and discuss the existing constraints on tensions from operating CMB B-Mode probes and the expected ones for the future network of...
I will review theoretical models for axions that solve the puzzles of the Standard Model, and discuss their cosmological implications.
In this talk, I will describe my efforts to understand the nature of the mysterious dark matter, using the assumption that dark matter is comprised of ultralight axions. From the optical to the X-ray and gamma-ray universe, astrophysics has a role to play in understanding the details of this major problem in particle physics. I will give some insight into how I am using a range of tools to get...
QCD axion is a hypothetical particle proposed to solve the strong CP problem and one well-motivated dark matter candidate for killing two birds with one stone. The Axion Dark Matter eXperiment (ADMX) builds axion haloscopes to search in the golden parameter space for the post-inflation scenario, probing the conversion of axions into photons stimulated by a large magnetic field. We have reached...
Dark photons have emerged as promising candidates for dark matter, and their search is a top priority in particle physics, astrophysics, and cosmology. We report the first use of a tunable niobium superconducting radio-frequency cavity for a scan search of dark photon dark matter with innovative data analysis techniques. We mechanically adjusted the resonant frequency of a cavity submerged in...
A theoretical solution to a long-standing puzzle in quantum chromodynamics, known as the strong CP problem, have led to the proposition of a hypothetical pseudo-Goldstone boson, the axion. Additionally, axions have growing attention due to their potential role as cold dark matter in our Universe. Interestingly, theoretical prediction to the axion mass from different research groups overlap...
Light dark matter, whose mass is typically less than ~1 meV, is becoming one of the attractive candidates since there is no evidence for the detection of the Weakly Interacting Massive Particle (WIMP). It has a long coherence length. Therefore, it is called wavy dark matter and the approach for it is different from the WIMP searches. Now, many experiments are searching for wavy dark matter...
In this invited talk I will review the state of the art and how the DALI experiment, currently in the design and prototyping phase, may play a role in the search for axion dark matter in a post-inflationary scenario.
The axion is a compelling candidate for cold dark matter and a favored solution to the strong CP problem. In this talk, I overview Dark Matter Radio (DMRadio), a campaign to search for the coupling of axion dark matter to electromagnetism at masses below 1 ueV. I discuss the status of DMRadio-50L, which will begin data-taking in 2024, and DMRadio-m3, under design as part of the DOE Dark Matter...
With the success of ABRACADABRA-10cm as a lumped-element axion dark matter experiment, two experimental upgrades are underway. DMRadio-50L will further our sensitivity to low mass axion dark matter with the addition of a tunable LC resonator to couple into the axion field in the presence of a toroidal magnet. We are also using the ABRACADABRA detector to electrodynamically search for...
Axion and Dark Photon (DP) have been considered as well-motivated dark matter candidates. Both hypothetical particles, if exist, are characterized by extremely feeble interactions with photons, rendering them suitable candidates for direct dark matter detection.
In this presentation, we introduce a new experimental strategy aimed at the detection of both axions and Dark Photons. This approach...
We plan to search for axion dark matter through their interactions with electron spins. Axion wind from the dark matter halo in our galaxy creates an effective magnetic field that induces quanta of collective electron spin wave excitations called magnons in ferromagnetic crystals like Yttrium Iron Garnet (YIG). We plan to observe these axion-induced magnons using a hybrid magnon - photon -...
