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Astronomy & Astrophysics
George Lazarides, Rinku Maji, Rishav Roshan, Qaisar Shafi
Summary: Inspired by the recent determination of the W-boson mass, this study revisits an SO(10) axion model and finds that a scalar SU(2)(L) triplet field can significantly contribute to the W mass, thereby resolving the discrepancy between the Standard Model prediction and the experimental measurement. The model also satisfies gauge coupling unification and observable proton decay, and predicts the existence of axion and stable intermediate mass fermion as dark matter candidates. Furthermore, the model predicts the gravitational wave spectrum from topologically stable cosmic strings.
Article
Astronomy & Astrophysics
Bartlomiej Kiczek, Marek Rogatko, Karol Wysokinski
Summary: Using the gauge-gravity duality to explore the properties of a holographic superconducting quantum device influenced by dark matter, researchers have observed a small but visible effect on the device's maximal current when a dark matter particle traverses it.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Multidisciplinary
G. Mustafa, Abdelghani Errehymy, S. K. Maurya, M. K. Jasim, Allah Ditta
Summary: This manuscript explores the physical aspects of compact stars in f(tau, T) gravity using the Karori-Barua spacetime. It considers three specific compact star models and examines their physical acceptability through calculations and graphical analyses. The results show that the obtained solutions are physically viable and have good properties.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Astronomy & Astrophysics
Andrea Calcinari, Steffen Gielen
Summary: In cosmological group field theory (GFT), the total volume as a function of the scalar field follows classical dynamics at low energies and resolves the Big Bang singularity at high energies. This study takes the first steps towards studying anisotropic Bianchi models in GFT by introducing a new anisotropy observable, similar to beta variables in Misner's parametrization. The results suggest the possibility of defining relational dynamics in GFT without the need for matter.
CLASSICAL AND QUANTUM GRAVITY
(2023)
Article
Astronomy & Astrophysics
Alexandros Karam, Martti Raidal, Eemeli Tomberg
Summary: The study focuses on preheating in plateau inflation in a scenario similar to Higgs inflation, revealing that the oscillating inflaton field repeatedly returns to the plateau, leading to tachyonic production of inflaton particles. Moreover, it is demonstrated that a minimally coupled spectator scalar field can be more efficiently produced through a similar mechanism. The mechanism is solely gravitational and the scalar field mass can be as high as 10^13 GeV, making it a candidate for superheavy dark matter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Multidisciplinary
A. V. Babich, V. F. Klepikov
Summary: A new class of models is proposed to describe the phase transitions in anisotropic multidimensional systems with higher-order spatial order parameter derivatives and higher order parameter nonlinearities. These models are potentially valuable for studying phase transitions in early universe cosmology, inflation cosmology, superstring, p-branes, and other non-point objects theories. The upper and lower critical dimensions of the models have been calculated to determine the applicability of mean-field theory in describing critical phenomena in these models.
Article
Physics, Particles & Fields
Maria Ortiz-Banos, Mariam Bouhmadi-Lopez, Ruth Lazkoz, Vincenzo Salzano
Summary: This study explores a modified theory of gravity with non-minimal coupling to matter, showing that gravitational coupling to matter can drive accelerated expansion of the universe. Analytical solutions for the functions f1 and f2 were calculated for different energy density contents, supporting the conclusion. Cosmographic analysis was also performed to further understand the impact of gravitational coupling.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Tahereh Azizi, Najibe Borhani, Mojtaba Haghshenas
Summary: We study specific models of non-minimal matter-geometry coupling theories and examine the behavior of gravitational waves in these models. By analyzing the temporal evolution of the gravitational wave equation in a flat FRW universe with a perfect fluid distribution, we observe the decay of both amplitude and frequency of the gravitational waves over time. The rate of decay is found to depend on the equation of state parameter and input parameters of the models.
PHYSICS OF THE DARK UNIVERSE
(2023)
Article
Astronomy & Astrophysics
Omer Guleryuz
Summary: In this work, an effective field theory for string inflation with spontaneously broken supersymmetry is presented, without generating any supersymmetric anti-de Sitter vacua. The analysis of nilpotent superfields effectively captures the physics of anti-D3 branes and reveals a novel uplifting method by adding the same parameter as a complex contribution parallel to the decomposition of a superfield. With almost vanishing cosmological constant in the region where the inflationary attractors unify, the introduction of nilpotent superfields drastically extends the string landscape for the de Sitter (swampland) conjecture.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Multidisciplinary
M. J. S. Houndjo, M. G. Ganiou, F. M. Kombetto, J. Tossa
Summary: In this paper, we investigate the f(T) theory of gravity coupled with scalar field and its reconstruction in the context of an exponential evolution of the scale factor. The impact of algebraic function on the slow-roll parameters is analyzed, and the results demonstrate the consistency of the reconstructed model with the recent data.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Physics, Particles & Fields
A. Ramos, C. Arias, E. Fuenmayor, E. Contreras
Summary: This work investigates class I interior solutions supported by anisotropic polytropes by solving the generalized Lane-Emden equation and computing the Tolman mass. The impact of the Karmarkar condition on mass and Tolman mass functions is also considered, with comparisons made to other literature results.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Osmin Lacombe, Shinji Mukohyama
Summary: This study investigates theories of gravity involving metric and scalar fields, allowing for direct couplings between these scalar fields and the matter sector. The weak gravity regime of this theory is analyzed using the parametrized post-Newtonian formalism. It is found that non-relativistic probes deviate from the geodesics in the PPN metric when direct couplings differ between the source and probe of gravity.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Javad Tabatabaei, Abdolali Banihashemi, Shant Baghram, Bahram Mashhoon
Summary: Within the framework of local limit of nonlocal gravity, we investigate a class of spatially homogeneous but anisotropic cosmological models, exploring the modified field equations and their solutions, as well as the contribution of the susceptibility function to cosmic acceleration. The implications for observational cosmology are briefly discussed.
Article
Astronomy & Astrophysics
P. H. R. S. Moraes, G. Panotopoulos, I Lopes
Summary: This study investigates the properties of exotic stars made entirely of dark matter, considering intrinsic anisotropies that have been ignored so far. Semi-analytical solutions to the structure equations are obtained, showing that these solutions behave well within general relativity and can describe realistic astrophysical configurations. A direct comparison with isotropic counterparts with the same radius reveals that the latter are slightly more massive.
Article
Astronomy & Astrophysics
I-Kang Liu, Nick P. Proukakis, Gerasimos Rigopoulos
Summary: We find that fuzzy dark matter haloes exhibit spatial differentiation in coherence, with complete coherence in the central solitonic core and incoherence outside of it. The phase-space density decreases significantly as the radius increases. The core is a pure condensate, overlapping perfectly with the largest eigenvalue of the one-particle density matrix. The outer halo consists of local, short-lived quasi-condensate lumps called granules, separated by vortices that form a dynamic web, inhibiting phase coherence throughout the entire halo.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
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Physics, Nuclear
S. Kalyana Rama
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