Article
Astronomy & Astrophysics
Philip Bull, Martin White, Anze Slosar
Summary: This study investigates constraints on the behavior of dynamical dark energy in the matter-dominated era, finding that existing CMB and LSS measurements have constrained the dark energy equation of state during this period. It also examines how forthcoming galaxy surveys and 21cm intensity mapping instruments can further improve constraints in this regime.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Prolay Chanda, James Unwin
Summary: In this paper, the scenario in which Asymmetric Dark Matter (ADM) decouples from the Standard Model thermal bath during an early period of matter domination is explored. Model independent analysis and a specific example in the context of an elegant SO(10) implementation are presented and contrasted with conventional ADM models. The prospects for superheavy ADM in this setting are discussed in the concluding remarks.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Multidisciplinary
A. K. Yadav, G. K. Goswami, A. Pradhan, S. K. Srivastava
Summary: This paper investigates a spatially homogeneous and isotropic quintessence Universe in Lyra geometry that fits well with latest observations. The transition from early deceleration to present acceleration phase is attributed to the appearance of dark energy, in agreement with current observations. The study also discusses some physical and geometrical properties of the Universe, concluding that the displacement vector beta is not responsible for late time acceleration.
INDIAN JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Avik Banerjee, Debtosh Chowdhury
Summary: We study the impact of an alternate cosmological history with an early matter-dominated epoch on the freeze-in production of dark matter. It is found that orders of magnitude larger coupling between the visible and the dark sector can be accommodated in this scenario, compared to the usual case of dark matter production in a radiation-dominated universe.
Article
Physics, Particles & Fields
A. Abada, G. Arcadi, M. Lucente, G. Piazza, S. Rosauro-Alcaraz
Summary: This study presents a detailed analysis of dark matter production through the decay of heavy right-handed neutrinos, leading to the formation of a sterile neutrino via freeze-in. The researchers found that the production of dark matter is not as suppressed when considering thermal effects in the effective couplings of the new heavy neutrinos with the Standard Model particles. Their findings suggest that the freeze-in mechanism for dark matter production can be efficient.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Jorge Sanchez Almeida, Angel R. Plastino, Ignacio Trujillo
Summary: According to the current cosmological model, dark matter particles produce self-gravitating structures with a central cusp. However, observations show that the density tends to a central plateau or core, which can be explained by the gravitational feedback of baryons on dark matter. This mechanism becomes inefficient for low-mass galaxies, and if cores exist in these galaxies, they reflect departures from the collisionless nature of dark matter.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Antonio Capolupo, Sante Carloni, Aniello Quaranta
Summary: This study analyzes fermion mixing within the framework of field quantization in curved spacetime. The authors compute the expectation value of the energy-momentum tensor of mixed fermions on the flavor vacuum and demonstrate that it can be interpreted as the effective energy-momentum tensor of a perfect fluid. The equation of state of the fluid is consistent with that of dust and cold dark matter assuming a fixed de Sitter background. These findings establish a new connection between quantum effects and classical fluids, suggesting that the flavor vacuum of mixed fermions may be a new component of dark matter.
Article
Mechanics
Davide Vigano, Luca Maddalena
Summary: Streamwise vortices are being studied for enhancing air/fuel mixing and controlling turbulence production in supersonic flows. Specific modes of vortex interaction can sustain turbulence by influencing the mean flow strain rates, which are coupled with Reynolds stresses. An experimental methodology using strain rates and Reynolds stresses tensors eigendecomposition was proposed as a quantitative approach for selecting supersonic streamwise vortices configurations that sustain turbulence.
Article
Astronomy & Astrophysics
Priyanka Adhikary, Sudipta Das, Spyros Basilakos, Emmanuel N. Saridakis
Summary: The study discusses the construction of Barrow holographic dark energy in nonflat universe, deriving differential equations for the evolution of dark-energy density parameter and providing analytical expression for the dark energy equation-of-state parameter. The scenario is shown to describe the thermal history of the universe and the sequence of matter and dark energy epochs. Comparisons with flat cases and different spatial geometries reveal interesting behaviors in the evolution of dark-energy equation-of-state parameters under Barrow exponent variations. Incorporating slightly non-flat spatial geometry improves the phenomenology of Barrow holographic dark energy while maintaining smaller values for the new Barrow exponent.
Article
Geosciences, Multidisciplinary
Rajan K. Chakrabarty, Nishit J. Shetty, Arashdeep S. Thind, Payton Beeler, Benjamin J. Sumlin, Chenchong Zhang, Pai Liu, Juan C. Idrobo, Kouji Adachi, Nicholas L. Wagner, Joshua P. Schwarz, Adam Ahern, Arthur J. Sedlacek, Andrew Lambe, Conner Daube, Ming Lyu, Chao Liu, Scott Herndon, Timothy B. Onasch, Rohan Mishra
Summary: Observations of smoke plumes in the United States shows that atmospheric short-wave absorption due to wildfire smoke is mainly caused by dark brown carbon particles. Wildfires release large amounts of black carbon and light-absorbing organic carbon, known as brown carbon, into the atmosphere, which disrupts Earth's radiation budget. It is important to quantify these radiative impacts as wildfires are predicted to increase globally.
Article
Physics, Particles & Fields
Shu-Yu Ho
Summary: In this paper, the authors construct the first model of asymmetric strongly interacting massive particle (SIMP) dark matter, which consists of a new vector-like fermion and a new complex scalar. By adding an additional complex scalar as a mediator, the model can explain the relic density of dark matter, exhibit a bouncing effect on dark matter, and predict a self-interacting cross section consistent with astrophysical observations. The authors also predict the elastic scattering cross section between dark matter and electrons for future experiments.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Eduardo Gonzalo, Miguel Montero, Georges Obied, Cumrun Vafa
Summary: This study explores the cosmological aspects of the Dark Dimension and proposes the existence of dark gravitons as a potential dark matter candidate. By analyzing the generic features of the dark dimension cosmology, the study provides a natural explanation for the correct dark matter density and the resolution of the cosmological coincidence problem.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Avirup Ghosh, Satyanarayan Mukhopadhyay
Summary: Postinflationary reheating affects the momentum distribution of dark matter particles through scattering processes, making it significantly different from the one obtained at reheating. The coupling between the inflaton and standard model fields plays a crucial role in these scattering effects.
Article
Astronomy & Astrophysics
Yann Mambrini, Keith A. Olive
Summary: This study investigates the direct s-channel gravitational production of dark matter during the reheating process, finding that the abundance of dark matter primarily depends on the combination T-max(4)/TRHMP3 and can be produced at sufficient densities over a wide range of dark matter masses, from 1 GeV to 1 ZeV.
Article
Multidisciplinary Sciences
Cosmin Andrei, Anna Ijjas, Paul J. Steinhardt
Summary: In this paper, we investigate how short the remaining period of expansion can be given current observational constraints on dark energy, and discuss how this scenario fits naturally with cyclic cosmologies and recent conjectures about quantum gravity.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
