Article
Astronomy & Astrophysics
Ernest Ma, Valentina De Romeri
Summary: The singlet Majoron model incorporates a dark matter fermion and a dark matter boson, with the fermion obtaining its mass through a radiative process anchored by heavy right-handed neutrinos. The freeze-in mechanism for the fermion to be light dark matter of the Universe is provided by the one-loop decay of the standard model Higgs boson into fermions.
Article
Physics, Particles & Fields
Asmaa Abada, Nicolas Bernal, Antonio E. Carcamo Hernandez, Xabier Marcano, Gioacchino Piazza
Summary: We propose an economical model that addresses the generation of the Inverse Seesaw mechanism from the spontaneous breaking of a local U(1)(B-L), with radiatively generated Majorana masses of sterile neutrinos from the dark sector. The model extends the field content of the Standard Model with neutral scalars and fermionic singlets, and extends the gauge group with a U(1)(B-L) and discrete Z(4) symmetries. The model complies with bounds and constraints from dark matter direct detection, invisible Higgs decays, and Z' collider searches for masses of the dark sector at the TeV scale.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Phung Van Dong, Cao H. Nam, Duong Van Loi
Summary: The canonical seesaw mechanism via U(1)(B-L) gauge symmetry can naturally provide two-component dark matter. The dark matter components transform nontrivially under matter parity and Z(3) symmetry, allowing for arbitrary masses.
Article
Astronomy & Astrophysics
Celine Boehm, Xiaoyong Chu, Jui-Lin Kuo, Josef Pradler
Summary: The study revisited the possibility of light-scalar dark matter coupled to electrons through fermion or vector mediators, and established new limits and loop-induced processes strengths. Various constraints were considered, largely excluding the explanation of the International Gamma-Ray Astrophysics Laboratory excess of 511 keV photons by galactic annihilation of these particles.
Article
Physics, Particles & Fields
E. Fernandez-Martinez, M. Pierre, E. Pinsard, S. Rosauro-Alcaraz
Summary: This study analyzes the inverse Seesaw scenario for neutrino masses, where the Lepton number symmetry is broken dynamically by a scalar with Lepton number two, and shows how the associated Majoron can alleviate the Hubble tension. Additionally, it suggests that sterile neutrinos at the keV-MeV scale can explain all the dark matter component of the Universe if produced via freeze-in from the decays of heavier degrees of freedom.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Carlos Jaramillo, Manfred Lindner, Werner Rodejohann
Summary: This study investigates the potential role of right-handed neutrinos as dark matter in the Universe and explores the possibility of their generation through the freeze-out production mechanism. It is found that if the neutrino Yukawa coupling is large in the early Universe to thermalize the sterile neutrinos, and then becomes tiny at a certain moment, they can drop out of equilibrium and potentially become stable on cosmological time scales. The proposed mechanism is shown to work for a wide range of sterile neutrino masses.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Talal Ahmed Chowdhury, Shaaban Khalil, Ernest Ma
Summary: The scotogenic model of neutrino mass is modified to allow the dark Majorana fermion singlet S, which gives the neutrino its mass, to be self-generated in one loop.
Article
Astronomy & Astrophysics
Rupert Coy, Aritra Gupta, Thomas Hambye
Summary: In this article, we demonstrate that the dark matter relic density can be produced through freeze-in within the usual type-I seesaw framework, augmented solely by a neutrino portal interaction. This simple freeze-in scenario, where dark matter is not in a seesaw state, involves slow, seesaw-induced decays of Higgs W and Z bosons. We identify two scenarios, with one predicting the existence of an observable neutrino line.
Article
Astronomy & Astrophysics
Cesar Bonilla, A. E. Carcamo Hernandez, Bastian Diaz Saez, Sergey Kovalenko, Juan Marchant Gonzalez
Summary: In this study, we propose a Majoron-like extension of the Standard Model where neutrino masses are generated through an inverse seesaw mechanism. We explore the case of Majorana fermions as dark matter candidates in this framework. Additionally, we provide parameter space regions that satisfy current experimental constraints.
Article
Astronomy & Astrophysics
Rupert Coy, Thomas Hambye, Michel H. G. Tytgat, Laurent Vanderheyden
Summary: The paper investigates the possible parameter space of thermal dark matter candidates, defining their range based on model-independent theoretical considerations and observational constraints. Three simplified dark matter scenarios are presented in the paper to demonstrate their fit into the domain.
Article
Physics, Multidisciplinary
Haiying Cai, Giacomo Cacciapaglia, Seung J. Lee
Summary: In this study, we present our discovery of a chiral enhancement in the production cross sections of massive spin-2 gravitons below the electroweak symmetry breaking scale, which makes them ideal dark matter candidates for the freeze-in mechanism. The result is independent of physics at high scales and points to graviton masses in the keV-MeV range, suggesting that gravitons could be sub-MeV dark matter particles, consistent with the preferred scale of small galaxy structures. We apply this novel calculation to a Randall-Sundrum model with multiple branes, demonstrating a significant parameter space where the first two massive gravitons saturate the dark matter relic density.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Rupert Coy, Aritra Gupta
Summary: In this study, we demonstrate a one-to-one correspondence between dark matter physics and the seesaw parameters controlling neutrino masses in simple neutrino portal extensions of the Standard Model. We investigate the scenarios of freeze-in and relativistic freeze-out processes. The allowed regions for the neutrino portal coupling are identified, and the parameter space is further constrained by observational and theoretical considerations. Additionally, a distribution function for a doubly frozen-in particle is derived to improve the calculation of its free-streaming horizon.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Particles & Fields
M. Chianese, B. Fu, S. F. King
Summary: This paper presents a minimal type Ib seesaw model and proposes an extension introducing dark matter into the model, exploring the parameter space for dark matter production. The connection between dark matter production and laboratory experiments is discussed, especially in relation to the mixing between standard model neutrinos and heavy neutrinos. Parameters related to dark matter production are constrained by experimental results and can be tested further in future experiments such as SHiP.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Pei-Hong Gu
Summary: The study suggests that a TeV-scale Higgs doublet with a small mixing to the standard model Higgs doublet can have sizable Yukawa couplings to several right-handed neutrinos and standard model lepton doublets, providing a testable Dirac neutrino mass generation mechanism. The study further considers a seesaw mechanism involving a U(1)(B-L) gauge symmetry, predicting the existence of two right-handed neutrinos and a stable Dirac fermionic dark matter to simultaneously explain the small mixing between the two Higgs doublets and the generation of cosmic baryon asymmetry.
Article
Astronomy & Astrophysics
XinXin Qi, Hao Sun
Summary: Here we study a simple complex scalar singlet dark matter model with Z3 symmetry based on the type-II seesaw mechanism. We use the model to explain the excess of electron-positron flux measured by the AMS-02, DAMPE, and Fermi-LAT Collaborations, which is caused by the decay of the triplets produced from dark matter annihilations in the Galactic halo. By considering the nondegenerate case, in which the mass of dark matter is larger than that of the triplets, we deliberately alleviate the leptophilic properties of the dark matter and enhance the semiannihilation effects. With the restriction of Z3 symmetry, we find strong constraints on the dark matter cubic terms and the couplings between dark matter and the Higgs boson, leading to a semiannihilation cross-section fraction less than 11% when the dark matter mass is given at 2 TeV.
Article
Astronomy & Astrophysics
Nelson R. F. Braga, Octavio C. Junqueira
Summary: This study investigates the influence of rotation on the transition temperature of strongly interacting matter produced in non-central heavy ion collisions. By using a holographic description of an AdS black hole, the authors extend the analysis to the more realistic case where the matter spreads over a region around the rotational axis. The results show the coexistence of confined and deconfined phases and are consistent with the concept of local temperature in rotating frames developed by Tolman and Ehrenfest.
Article
Astronomy & Astrophysics
Bing Sun, Jiachen An, Zhoujian Cao
Summary: This paper investigates the effect of gravitational constant variation on the propagation of gravitational waves. By employing two analytical methods, the study finds that variations in the gravitational constant result in amplitude and phase corrections for gravitational waves, and the time variation of the gravitational constant can be constrained through the propagation of gravitational waves.
Article
Astronomy & Astrophysics
Abdellah Touati, Zaim Slimane
Summary: This letter presents the first study of Hawking radiation as a tunneling process within the framework of non-commutative gauge theory of gravity. The non-commutative Schwarzschild black hole is reconstructed using the Seiberg-Witten map and the star product. The emission spectrum of outgoing massless particles is computed using the quantum tunneling mechanism. The results reveal pure thermal radiation in the low-frequency scenario, but a deviation from pure thermal radiation in the high-frequency scenario due to energy conservation. It is also found that noncommutativity enhances the correlations between successively emitted particles.
Article
Astronomy & Astrophysics
Shahar Hod
Summary: The travel times of light signals between two antipodal points on a compact star's surface are calculated for two different trajectories. It is shown that, for highly dense stars, the longer trajectory along the surface may have a shorter travel time as measured by asymptotic observers. A critical value of the dimensionless density-area parameter is determined for constant density stars to distinguish cases where crossing through the star's center or following a semi-circular trajectory on the surface has a shorter travel time as measured by asymptotic observers.