PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·September 5, 2024

8 papers—4 primary·4 cross-listed

All8Primary4Cross-lists4
  1. 05

    Decoding Dark Matter Admixed Neutron Stars: From Static Structure to Rotational Deformation

    Pinku Routaray🇮🇳 · Abirbhav Chakrawarty🇮🇳 · N. K. Patra🇨🇳 · Bharat Kumar🇮🇳

    In this study, we investigate the impacts of dark matter (DM) on the properties of both static and rotating neutron stars utilizing a self-interacting DM model, motivated by the neutron decay anomaly. DM-admixed NSs are modeled by assuming chemical equilibrium between ordinary matter and the dark sector, treating a single-fluid Tolman-Oppenheimer-Volkoff (TOV) framework. By treating the DM interaction strength () as a free parameter, we explore its influence on NS properties, considering a broad range of equations of state (EoSs). Using the mass-radius constraints from NICER pulsar measurements, we constrain the DM interaction strength for each EoS via a likelihood analysis. Extending this model to rotating NSs, we analyze how centrifugal forces associated with increasing angular velocity () enhance both mass and radius, causing deformation. We assess the impact of DM on rotational deformation by calculating the eccentricity, highlighting the interplay between DM and rotational forces. Since both DM and rotation simultaneously influence NS properties, we compute the relative changes in mass and radius across varying and values to quantify their combined effects.

    ↳ astro-ph.HEgr-qchep-phnucl-thPhys.Dark Univ.(2025)·10 citations
  2. 06

    Origins and impacts of dynamical diquark correlations -- A continuum Schwinger functional approach --

    Jorge Segovia🇪🇸

    This conference proceedings contribution emphasizes the emergent hadron mass paradigm, which accounts for the majority of the visible mass in the universe, beyond the Higgs boson mechanism. The study delves into the Landau gauge gluon propagator and the dynamical generation of gluon mass, as well as the dressed-quark propagator and dynamical chiral symmetry breaking. It also tackles the baryon bound state problem through the Poincaré-covariant Faddeev equation, analyzing the composition and masses of octet and decuplet baryons. The document concludes with a discussion on the electromagnetic form factors of the nucleon and its first radial excitation, providing insights into the quark-diquark structure within baryons.

    ↳ hep-phhep-exhep-latnucl-ex+1PoS(2025)·0 citations
  3. 07

    Anisotropic pressure effect on central EOS of PSR J0740+6620 in the light of dimensionless TOV equation

    Zhihao Yang · Dehua Wen

    It is generally agreed upon that the pressure inside a neutron star is isotropic. However, a strong magnetic field or superfluidity suggests that the pressure anisotropy may be a more realistic model. We derived the dimensionless TOV equation for anisotropic neutron stars based on two popular models, namely the BL model and the H model, to investigate the effect of anisotropy. Similar to the isotropic case, the maximum mass and its corresponding radius can also be expressed linearly by a combination of radial central pressure and central energy density , which is insensitive to the equation of state (EOS). We also found that the obtained central EOS would change with different values of (), which controls the magnitude of the difference between the transverse pressure and the radial pressure. Combining with observational data of PSR J0740+6620 and comparing to the extracted EOS based on isotropic neutron star, it is shown that in the BL model, for = 0.4, the extracted central energy density changed from 546 -- 1056 MeV/fm to 510 -- 1005 MeV/fm, and the extracted radial central pressure changed from 87 -- 310 MeV/fm to 76 -- 271 MeV/fm. For = 2, the extracted and changed to 412 -- 822 MeV/fm and 50 -- 165 MeV/fm, respectively. In the H model, for = 0.4, the extracted changed to 626 -- 1164 MeV/fm, and the extracted changed to 104 -- 409 MeV/fm. For = 2, the extracted decreased to 894 -- 995 MeV/fm, and the extracted changed to 220 -- 301 MeV/fm.

    ↳ astro-ph.HEastro-ph.SRnucl-thCPC(2024)·2 citations
  4. 08

    Configurational entropy and stability conditions of fermion and boson stars

    P.S. Koliogiannis🇭🇷 · M. Vikiaris🇬🇷 · C. Panos🇬🇷 · V. Petousis🇨🇿 · M. Veselsky🇨🇿 · Ch.C. Moustakidis🇬🇷

    In a remarkable study by M. Gleiser and N. Jiang [Phys. Rev. D {\bf 92}, 044046, 2015], the authors demonstrated that the stability regions of neutron stars, within the framework of the simple Fermi gas model, and self-gravitating configurations of complex scalar field (boson stars) with various self couplings, obtained through traditional perturbation methods, correlate with critical points of the configurational entropy with an accuracy of a few percent. Recently, P. Koliogiannis \textit{et al.} [Phys. Rev. D {\bf 107}, 044069 2023] found that while the minimization of the configurational entropy generally anticipates qualitatively the stability point for neutron stars and quark stars, this approach lacks universal validity. In this work, we aim to further elucidate this issue by seeking to reconcile these seemingly contradictory findings. Specifically, we calculate the configurational entropy of bosonic and fermionic systems, described by interacting Fermi and boson gases, respectively, that form compact objects stabilized by gravity. We investigate whether the minimization of configurational entropy coincides with the stability point of the corresponding compact objects. Our results indicate a strong correlation between the stability points predicted by configurational entropy and those obtained through traditional methods, with the accuracy of this correlation showing a slight dependence on the interaction strength. Consequently, the stability of compact objects, composed of components obeying Fermi or boson statistics, can alternatively be assessed using the concept of configurational entropy.

    ↳ gr-qcastro-ph.HEnucl-thphysics.comp-phPRD(2024)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE