Fri - 01/31/25

There is no new related paper today

There is no new related paper today

  1. [] - Title: Supersymmetric Grey Galaxies, Dual Dressed Black Holes and the Superconformal Index - Sunjin Choi, Diksha Jain, Seok Kim, Vineeth Krishna, Goojin Kwon, Eunwoo Lee, Shiraz Minwalla, Chintan Patel

Thu - 01/30/25

There is no new related paper today

There is no new related paper today

Wed - 01/29/25

**Title:

      Two-Measure Electroweak Standard Model. Some aspects of cosmological evolution and vacuum stability**  - **Authors:** Alexander B. Kaganovich  - **Subjects:** Subjects: High Energy Physics - Theory (hep-th)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  In the FLRW universe, the scalar field \phi(t) obtained by cosmological averaging of the local Higgs field $H(x)$ is considered as a classical field for which the SM quantization procedure is meaningless. When applying the Two-Measure theory (TMT) to study cosmology, the ratio \zeta of the measure densities is a scalar function, which: enters into all equations of motion. Through the constraint, \zeta is defined as a function of \phi(t). During cosmological evolution, \zeta(\phi) changes from \zeta\approx 0 at the inflationary stage to \zeta=1 at the approaching vacuum stage. Each stage of the classical cosmological background is determined by the set {\phi(t), curvature, \zeta(\phi(t))}. The Two-Measure SM (TMSM) is realized in the context of cosmology as a set of cosmologically modified copies of the GWS model. Each of the copies exists as a local quantum field theory defined on the classical cosmological background at the appropriate stage of its evolution. This basic idea is studied in detail for the stage of slow-roll inflation and for the stage of approaching vacuum. Due to the presence of \zeta(\phi(t)) in all equations of motion, all TMSM coupling constants turn out to be running (classical) TMT-effective parameters. During cosmological evolution, changing these parameters yields new results: the classical running TMT-effective Higgs selfcoupling increases from \lambda\sim 10^{-11} (which ensures consistency with the Planck's CMB data at \xi=\frac{1}{6}) to \lambda\sim 0.1 near vacuum; the mass term in the Higgs potential changes sign from positive to negative, providing standard SSB; the classical running gauge and Yukawa coupling constants change by several orders of magnitude; the GWS theory is reproduced so that the fermion mass hierarchy is obtained quite naturally. One-loop quantum corrections preserves the slow-roll inflation and does not violate the vacuum stability.

**Title:

      Properties of 4D spinfoam quantum geometry: Results from next-to-leading order spinfoam large-$j$ asymptotics of 1-5 Pachner move**  - **Authors:** Haida Li, Muxin Han, Hongguang Liu, Shicong Song, Dongxue Qu  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  This paper proposes several criteria to probe the non-trivialities of 4-dimensional geometry that impact spinfoam amplitude. These criteria include the standard deviation of 4-volumes of the constituting 4-simplices, the smallest 4-simplex volume, and whether the directions of tetrahedron 4-normals are close to the null direction. By numerically computing and analyzing the spinfoam amplitudes up to the next-to-leading order of 1-5 Pachner move samples with the same boundary 4-simplex, we reveal the relationship between 4-dimensional geometry and spinfoam amplitudes, as large standard deviation of 4-simplex volumes and small 4-simplex volume can result in both leading order and next-to-leading order amplitudes being large. Furthermore, the numerical result indicates that the distance from tetrahedron 4-normals to the null direction has a greater impact on increasing the next-to-leading order amplitude than on the leading order amplitude, making it primarily a quantum effect.
  1. [] - Title: Holographic Einstein Ring of Quantum Corrected AdS-Reissner-Nordstrom Black Holes in Kiselev Spacetime - Jin-Yu Gui, Ke-Jian He, Xiao-Xiong Zeng

Tue - 01/28/25

**Title:

      The two-vertex model of loop quantum gravity: anisotropic reduced sectors**  - **Authors:** Iñaki Garay, Luis J. Garay, Diego H. Gugliotta  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  The so-called two-vertex model of loop quantum gravity has been analytically studied in the past within a U($N$) symmetry-reduced sector leading to a cosmological interpretation. In this work we study the simplest non-trivial two-vertex model (with four edges, i.e., $N=4$), using the spinorial formalism and twisted geometries to isolate the degrees of freedom and derive a canonical parametrization. We identify eight geometric parameters describing the polyhedral configurations and four twist angles characterizing the system's dynamics. Going beyond the U($N$) symmetry-reduced sector which can be interpreted as homogeneous and isotropic, we find three additional stable symmetry-reduced sectors: the privileged-direction sector, the bi-twist sector, and the inhomogeneous bi-twist sector. Each sector introduces degrees of anisotropy or inhomogeneity and expand the potential cosmological interpretations of the two-vertex model.

There is no new related paper today

Mon - 01/27/25

There is no new related paper today

There is no new related paper today

  1. [] - Title: Regular Black Hole from gravitational collapse of dust and radiation - Vitalii Vertogradov

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