Dark matter

Accurately predicting the abundance and structural evolution of dark matter subhaloes is crucial for understanding galaxy formation, large-scale structure, and constraining the nature of dark matter. Due to the nonlinear nature of subhalo evolution, cosmological N-body simulatio…

In the concordance model of modern cosmology, dark matter is five times as abundant as ordinary matter. While its nature remains one of the most challenging questions in today’s physics, dark matter has been established as a defining factor in the large-scale structure. Visible …

While Big Bang cosmology successfully explains much of the history of our Universe, there are certain features it does not explain, for example the spatial flatness and uniformity of our Universe. One widely studied explanation for these features is cosmological inflation. The o…

Dwarf galaxies are sensitive tests of the LCDM cosmological model and the physics of galaxy formation. We use numerical simulations to investigate the interaction between galaxies, their DM halos, and their satellites. We study zoom-in simulations from the Feedback In Realistic …

For the discovery of rare event physics processes related to new physics beyond the Standard Model, the next generation of physics experiments requires to be built underground. For instance, the Large Underground Xenon experiment and MAJORANA DEMONSTRATOR, both located undergrou…

In this dissertation, we investigated a vapor-liquid-solid (VLS) synthesis of high-density lead sulfide (PbS) NW arrays and nano pine trees directly on Ti thin films, and a fabrication of photovoltaic devices based upon the PbS NWs. The as-grown NW arrays are largely vertically …

The precise phase-space distribution and properties of Galactic dark matter necessary for its direct and indirect detection are currently unknown. Since the distributions of normal and dark matter in the Milky Way are coupled to each other as they both move in the same gravitati…

Supersymmetry (SUSY) is one of the most elegant extensions of the standard model (SM) of particle physics. It solves several problems in the SM, supports the idea of grand unification and also provides a candidate for dark matter. The recent discovery of the Higgs boson is consi…

Galaxy clusters, which originate from the highest density peaks in the primordial Universe, contain valuable information on cosmology. They are fascinating objects in their own right as they involve an interplay of the physics of dark matter, gas and galaxies. Their complex form…

The philosopher Galen Strawson and the author Philip Pullman explore the point of view that entities such as human beings and subatomic particles have subjective experience. The former scholar explores this theory through philosophical argumentation, and the latter scholar explo…

There is a long and rewarding history in astronomy of studying the motions of stars, gas, and planets to learn about the distribution of mass in the universe. Observations of nearby galaxies rotating faster than otherwise expected are one of the pillars of evidence for the cold …

The desire to unveil the mystery of dark matter which, according to compelling astrophysical and cosmological evidence, constitutes about 85% of the matter in the Universe, drives physicists to continuously develop their tools and search methodologies. There are several proposed…

In this thesis, we have studied gauged and geometric vector fields at the MeV scale in two main parts. The basic framework of these two parts are given briefly as follows. In the first part (Chapter 2), we have built a family-nonuniversal U(1) model populated by an MeV-scale sec…

I present an overview of the tools and methods of gravitational dynamics motivated by a variety of dynamics problems. Particular focus will be given to the development of dynamic phase-space configurations as well as the distribution functions of collisionless systems. Chapter 1…

Despite the many successes of the current standard model of cosmology on the largest physical scales, it relies on two phenomenologically motivated constituents, cold dark matter and dark energy, which account for approximately 95% of the energy-matter content of the universe. F…

The next generation of neutrinoless double beta (0νββ) decay experiments and direct detection of dark matter require ultrapure detectors. The University of South Dakota is leading the development of ultra-pure germanium crystals. The project includes purification work through zo…

In the standard thermal history of the Universe, the energy density is dominated by radiation throughout the postinflationary era, until matter-radiation equality after big bang nucleosynthesis (BBN). However, we currently do not have any observational probes of the pre-BBN peri…

The Heavy Photon Search (HPS) experiment is based out of the Thomas Jefferson National Accelerator Laboratory in Newport News and is designed to test the potential existence of a new particle, the "heavy photon" or "A'," which has the potential to mediate interactions between da…

The genesis and history of the Universe cannot be explained by the Standard Model (SM) of particle physics, as confirmed by an overwhelming amount of astrophysical and cosmological observations. At the same time, a clear signal of new physics has yet to be seen in dedicated terr…

We explore physics Beyond the Standard Model in the dark matter and in the neutrino sectors. In both cases, we parametrize New Physics effects at low energy experiments with an Effective Field Theory (EFT) approach. We then propose a dynamical solution of the fermion mass hierar…