Article
Astronomy & Astrophysics
J. Sedaghat, S. M. Zebarjad, G. H. Bordbar, B. Eslam Panah
Summary: We have performed a leading order perturbative calculation to obtain the equation of state (EoS) of strange quark matter (SQM) at zero temperature under a magnetic field B = 10(18) G. The obtained EoS is then used to calculate the maximum gravitational mass and corresponding radius of a magnetized strange quark star (SQS). The results show a maximum gravitational mass over three times the solar mass, and the validity of isotropic structure calculations for SQS is investigated.
Article
Astronomy & Astrophysics
Marcio Ferreira, Renan Camara Pereira, Constanca Providencia
Summary: The study reveals that multiquark interaction channels have a significant impact on the properties of hybrid stars, with the interplay between eight-quark vector interactions and isovector-vector interactions playing a key role in determining the size and strangeness content of the quark core. Hybrid stars with large strangeness content and large quark cores may exist, particularly when the binary mass ratio is close to or greater than 0.85.
Article
Astronomy & Astrophysics
Francesco Di Clemente, Alessandro Drago, Prasanta Char, Giuseppe Pagliara
Summary: The study indicates that white dwarfs with a core of strange quark matter are stable if the star is not strongly perturbed and ordinary matter cannot transform into strange quark matter; however, if the star undergoes a violent process, the system becomes unstable and collapses into a strange quark star.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
J. E. Horvath, L. S. Rocha, L. M. de Sa, P. H. R. S. Moraes, L. G. Barao, M. G. B. de Avellar, A. Bernardo, R. R. A. Bachega
Summary: Recently, a very low-mass compact star named XMMU J173203.3-344518 was discovered inside the supernova remnant HESS J1731-347. Its tiny mass contradicts the minimum mass calculations of neutron stars generated by iron cores, suggesting that it may be a strange star. Comparisons with theoretical models and calculations show that XMMU J173203.3-344518 fits into the same quark star models as other compact stars, supporting the idea of homogeneous self-bound objects in nature.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Eduardo S. Fraga, Rodrigo da Mata, Savvas Pitsinigkos, Andreas Schmitt
Summary: We present a model for dense matter that incorporates strangeness and exhibits a chiral phase transition. The model parameters can be tuned to obtain a high-density phase resembling deconfined quark matter. Additionally, the model can be used to study dense matter under compact star conditions and investigate spatially inhomogeneous phases.
Article
Physics, Multidisciplinary
I Bombaci, A. Drago, D. Logoteta, G. Pagliara, I Vidana
Summary: The possibility of the low mass companion of the black hole in the source of GW190814 being a strange quark star has been investigated. It is viable within the two-families scenario where neutron stars and strange quark stars coexist. Strange quark stars and neutron stars fulfill different astrophysical and nuclear physics constraints.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Shu-Hua Yang, Chun-Mei Pi, Xiao-Ping Zheng
Summary: The study suggests that strange stars with a mirror-dark-matter core may be necessary to explain certain astronomical observations, while providing evidence for the existence of a dark-matter core inside compact stars under the standard MIT bag model.
Article
Astronomy & Astrophysics
Shu-Hua Yang, Chun-Mei Pi, Xiao-Ping Zheng, Fridolin Weber
Summary: The study shows that the QMDD model can describe the properties of strange stars when considering non-Newtonian gravity effects, with the model parameters constrained by observational data. Strange stars can exist within certain ranges of quark masses and non-Newtonian gravity parameters, but their maximum possible mass is limited, and the secondary component cannot be a static strange star.
Article
Physics, Nuclear
Peng-Cheng Chu, Yi-Nong Wang, Xiao-Hua Li, He Liu, Jia-Wei Zhang
Summary: In this study, we investigate the properties of strange quark matter at finite temperature under constant magnetic field using the quasiparticle model. We find that both temperature and magnetic field have significant effects on the thermodynamical properties of quark matter. Our results suggest that the maximum mass of protoquark stars increases during the heating process, and the core temperature of the maximum mass depends on different snapshots along the isentropic stages.
Article
Physics, Nuclear
D. Alvear Terrero, S. Lopez Perez, D. Manreza Paret, A. Perez Martinez, G. Quintero Angulo
Summary: Stable spheroidal configurations of magnetized strange stars were studied, with the highest values of the mass quadrupole moment corresponding to the intermediate mass regime, showing the biggest deviation in observables. These differences could potentially be used to distinguish models with and without magnetic fields.
Article
Astronomy & Astrophysics
Anil Kumar, Vivek Baruah Thapa, Monika Sinha
Summary: In this study, we investigate the properties of stars participating in double compact star merger events, considering an interacting model of stable strange quark matter. By modeling the matter and making it compatible with recent astrophysical observations, including compact star mass-radius and gravitational wave events, we find a new upper bound on the tidal deformability of a 1.4 M-circle dot strange star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ayan Banerjee, Takol Tangphati, Phongpichit Channuie
Summary: This study investigates the construction of strange stars in quark matter phases and quantifies the mass-radius diagram for static strange star models using two types of equations of state. The numerical calculation of the modified Tolman-Oppenheimer-Volkoff equations is performed in the context of 4D Einstein-Gauss-Bonnet gravity, where the GB term plays a significant role in gravitational dynamics.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Yu-Ying He, Xin-Jian Wen
Summary: The thermodynamics of finite size quark matter in the quasiparticle model is studied. An effective bag function is used to consider the medium effect to the confinement. Analytic surface tensions in strong magnetic fields are obtained using the multiple reflection expansion, showing anisotropic structures with splitting between longitudinal and transverse surface tensions. The anisotropy of surface tension can be enhanced by higher magnetic fields, and the surface tension is modified by an additional term related to the bag function.
Article
Astronomy & Astrophysics
Xu Wang, Abudushataer Kuerban, Jin-Jun Geng, Fan Xu, Xiao-Li Zhang, Bing-Jun Zuo, Wen-Li Yuan, Yong-Feng Huang
Summary: The study reveals that the tidal deformabilities of strange quark planets and dwarfs are smaller than their normal matter counterparts, with bare strange quark planets being hardly distorted by tidal forces. This highlights the effectiveness of identifying strange quark objects through searching for strange quark planets using gravitational wave observations.
Article
Materials Science, Multidisciplinary
M. K. Jasim, S. K. Maurya, Saibal Ray, Dibyendu Shee, Debabrata Deb, Farook Rahaman
Summary: This paper discusses the existence of a compact strange (quark) star within the framework of Einstein's General Theory of Relativity with the Tolman V metric potential and uses the simplest form of MIT Bag equation of state to represent strange quark matter distribution. Various physical features and stability criteria are studied for different strange star candidates, and results show consistency with energy conditions, TOV equation, and adiabatic index. Different physical parameters are also calculated for three consecutive values of Bag constant, with a focus on the properties of strange star candidates with B = 90 MeV/fm³.
RESULTS IN PHYSICS
(2021)
Article
Astronomy & Astrophysics
Lien Rodriguez-Lopez, Rolando Cardenas, Lisdelys Gonzalez-Rodriguez, Mayrene Guimarais, Jorge Horvath
Summary: The study examines the potential lethality of Gamma Ray Bursts on aquatic primary producers on Earth, suggesting that UV flash could significantly reduce phytoplankton biomass in the upper mixed layer of the world's oceans.
ASTRONOMISCHE NACHRICHTEN
(2021)
Article
Astronomy & Astrophysics
Jorge Ernesto Horvath, Livia S. Rocha, Antonio Bernardo, Rodolfo Valientim, Marcio Guilherme Bronzato de Avellar
Summary: In this presentation, an overview of neutron star origin events and masses was presented. It was shown that the distribution of neutron star masses requires multiple mass scales, with the highest value inferred from the sample being compatible with 2.5 solar masses. The talk discussed the possibility of very heavy neutron stars in nature and reviewed the connection between supernovae compact remnants and observed masses.
ASTRONOMISCHE NACHRICHTEN
(2021)
Article
Astronomy & Astrophysics
Milton Rojas Gamarra, Steven R. Gullberg, Monica Estrazulas, Jorge Horvath, Cesar A. Zen Vasconcellos
Summary: This contribution explores the connections between the conceptions about space, time, and Cosmos in history and the cosmogonic view of the Inka culture, emphasizing the importance of understanding and interpreting the Inka legacy within the context of Inka culture and its worldview.
ASTRONOMISCHE NACHRICHTEN
(2021)
Article
Astronomy & Astrophysics
M. G. B. de Avellar, P. P. B. Beaklini, S. P. Nunes, P. H. R. S. Moraes, M. Malheiro
Summary: This study proposes a new model for Fast Radio Bursts (FRBs) based on the sudden discharge of a charged young magnetar. By modeling the magnetar and calculating relevant physical parameters, the results suggest that this model can explain the FRB phenomenon.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. E. Horvath, P. H. R. S. Moraes, M. G. B. de Avellar, L. S. Rocha
Summary: This work revisits a model for repeating Fast Radio Bursts based on the release of energy provoked by the magnetic field dynamics affecting a magnetar's crust. The basics of the model are addressed by solving the propagation of perturbations approximately, quantifying the energetics and radiation, and suggesting more detailed studies of nonlinear soliton solutions. The emission of X-rays from SGR 1935+2154 is tentatively associated with a reconnection behind the propagation, and the strength of f-mode gravitational radiation excited by the event is quantified.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
J. E. Horvath
Summary: This study focuses on the Crab supernova in 1054 A.D. and suggests that the observed event can be explained by a precursor phenomenon emerging from large supernova sampling and low-mass progenitors. The explosion itself is likely a low-luminosity supernova from small iron core type, rather than an electron-capture event.
ASTROPHYSICS AND SPACE SCIENCE
(2022)
Article
Astronomy & Astrophysics
Ximena C. Abrevaya, Douglas Galante, Paula M. Tribelli, Oscar J. Oppezzo, Felipe Nobrega, Gabriel G. Araujo, Fabio Rodrigues, Petra Odert, Martin Leitzinger, Martiniano M. Ricardi, Maria Eugenia Varela, Tamires Gallo, Jorge Sanz-Forcada, Ignasi Ribas, Gustavo F. Porto de Mello, Florian Rodler, Maria Fernanda Cerini, Arnold Hanslmeier, Jorge E. Horvath
Summary: This study investigated the potential of halite crystals to protect microorganisms under vacuum and vacuum-ultraviolet radiation conditions. The results showed that halite can effectively protect microorganisms from harm, and the protective effect of halite is higher than that of crystals made from mixtures of salts. These findings suggest that halite crystals may serve as preservation structures on airless bodies or as vehicles for interplanetary transfer of microorganisms.
Article
Astronomy & Astrophysics
Lucas M. de Sa, Antonio Bernardo, Riis R. A. Bachega, Livia S. Rocha, Jorge E. Horvath
Summary: Binary population synthesis provides a way to study the effects of binary evolution models and initial parameter distributions on compact binary merger populations, and compare them to observed properties such as merger rates.
ASTRONOMISCHE NACHRICHTEN
(2023)
Article
Astronomy & Astrophysics
Antonio L. C. Bernardo, Laura Paulucci, Lucas M. M. de Sa, Jorge E. E. Horvath
Summary: The Strange Quark Matter (SQM) hypothesis suggests the existence of a new state of matter, where half of the down quarks become strange quarks under extreme pressure and density conditions. This study aims to characterize the fragmentation of SQM and track the quark configuration of the fragmented matter, utilizing a methodology to estimate the energy of each fragment based on the summed energy of constituent quarks, Coulomb interaction among quarks, and fragments' momenta.
ASTRONOMISCHE NACHRICHTEN
(2023)
Article
Astronomy & Astrophysics
Jorge E. Horvath, Antonio L. C. Bernardo, Riis R. A. Bachega, Lucas M. de Sa, Livia S. Rocha, Pedro H. R. S. Moraes
Summary: The lack of objects between 2 and 5 M-& ODOT; in the joint mass distribution, known as the mass gap, is believed to be the result of the characteristics of the supernova mechanism during their birth. However, recent observations suggest that the reported candidates within the gap may fill it, and the scarcity may be due to small sample statistics. In this study, we quantify the individual candidates and evaluate the joint probability of a mass gap. Our results confidently show that there is no mass gap. The existence of a relatively scarce population of objects and its relation to the formation processes, such as neutron star mergers and collapse of neutron stars to black holes, remains to be explored.
ASTRONOMISCHE NACHRICHTEN
(2023)
Article
Astronomy & Astrophysics
Jorge E. E. Horvath
Summary: In this article, we provide concluding remarks for the 10th edition of the IWARA Workshop, including highlights and comments meant to enrich and provide context to the oral scientific presentations.
ASTRONOMISCHE NACHRICHTEN
(2023)
Article
Astronomy & Astrophysics
Jorge E. Horvath, Rodrigo Rosas Fernandes, Thais E. Idiart
Summary: In this work, we examine the contradictory nature of the coexistence of microphysical quantum reality and macrophysical classical reality in modern Physics. After discussing fundamental concepts in Philosophy, we analyze the implications of the results in Quantum Mechanics, particularly the violations of Bell's theorem, and the fundamental and unsolved tension it creates between the micro and macro world.
ASTRONOMISCHE NACHRICHTEN
(2023)
Article
Astronomy & Astrophysics
L. M. de Sa, A. Bernardo, R. R. A. Bachega, J. E. Horvath, L. S. Rocha, P. H. R. S. Moraes
Summary: The lack of objects between 2 and £5 M in the joint mass distribution of compact objects, known as the mass gap, has been attributed to the supernova mechanism. Recent observations suggest that some candidates within the gap may fill it, indicating a possible scarcity that could be real or a result of small sample statistics. This study quantifies individual candidates and evaluates the joint probability of a mass gap, finding that an absolute mass gap does not exist to a very high confidence level. It remains uncertain if there will be a relative scarcity of objects in the future and how this population can be linked to formation processes.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Lucas M. de Sa, Antonio Bernardo, Riis R. A. Bachega, Livia S. Rocha, Pedro H. R. S. Moraes, Jorge E. Horvath
Summary: The study of compact object populations has made significant progress, with the determination of mass and merger detection. We now have a better understanding of the variety of systems hosting these objects and can evaluate their statistical nature and long-standing problems. This article provides an overview of the field, focuses on Galactic black holes, and offers an updated catalog of their masses and orbital parameters.
Article
Physics, Multidisciplinary
Tinggui Chen, Baizhan Xia, Dejie Yu, Chuanxing Bi
Summary: This study proposes a gradient phononic crystal structure for enhanced acoustic sensing. By breaking the symmetry of the PC structure, topologically protected edge states are introduced, resulting in topological acoustic rainbow trapping. The robustness and enhancement properties are verified numerically and experimentally.
