Fri - 02/03/23

There is no new related paper today

There is no new related paper today

  1. [2302.00677] - Shadows of new physics on Dirac materials, analog GUPs and other amusements - Alfredo Iorio, Boris Ivetić, Salvatore Mignemi, Pablo Pais

  2. [2302.00823] - Batalin-Tyutin quantization of dynamical boundary of AdS$_2$ - Wontae Kim, Mungon Nam

  3. [2302.01206] - Matrix and tensor witnesses of hidden symmetry algebras - Sanjaye Ramgoolam, Lewis Sword

Thu - 02/02/23

There is no new related paper today

Summing bulk quantum numbers with Monte Carlo in spin foam theories

  • Authors: Pietro Dona, Pietropaolo Frisoni
  • Subjects: General Relativity and Quantum Cosmology (gr-qc)
  • Arxiv link: https://arxiv.org/abs/2302.00072
  • Abstract We introduce a strategy to compute EPRL spin foam amplitudes with many internal faces numerically. We work with \texttt{sl2cfoam-next}, the state-of-the-art framework to numerically evaluate spin foam transition amplitudes. We find that uniform sampling Monte Carlo is exceptionally effective in approximating the sum over internal quantum numbers of a spin foam amplitude, considerably reducing the computational resources necessary. We apply it to compute large volume divergences of the theory and find surprising numerical evidence that the EPRL vertex renormalization amplitude is instead finite.

  1. [2302.00028] - Singularity-free gravitational collapse: From regular black holes to horizonless objects - Raúl Carballo-Rubio, Francesco Di Filippo, Stefano Liberati, Matt Visser

  2. [2302.00017] - Towers and Hierarchies in the Standard Model from Emergence in Quantum Gravity - Alberto Castellano, Álvaro Herráez, Luis E. Ibáñez

  3. [2302.00632] - Cosmic ER=EPR in dS/CFT - Jordan Cotler, Andrew Strominger

Wed - 02/01/23

There is no new related paper today

There is no new related paper today

  1. [2301.13502] - Parity-violation in bouncing cosmology - Mian Zhu, Yong Cai

  2. [2301.13525] - Higher-order curvature operators in causal set quantum gravity - Gustavo. P. de Brito, Astrid Eichhorn, Christopher Pfeiffer

  3. [2301.13627] - Tunneling and thermodynamics evolution of the magnetized Ernst-like black hole - Riasat Ali, Zunaira Akhtar, Kazuharu Bamba, M. Umar Khan

  4. [2301.13291] - Effective approach to the Antoniadis-Mottola model: quantum decoupling of the higher derivative terms - Wagno Cesar e Silva, Ilya L. Shapiro

  5. [2301.13580] - Horava models as palladium of unitarity and renormalizability in quantum gravity - Andrei O. Barvinsky

  6. [2301.13605] - Aspects of the map from Exact RG to Holographic RG in AdS and dS - Pavan Dharanipragada, Semanti Dutta, B.Sathiapalan

Tue - 01/31/23

There is no new related paper today

There is no new related paper today

  1. [2301.12455] - Axiomatic Quantum Field Theory in Discrete Spacetime via Multiway Causal Structure: The Case of Entanglement Entropies - Jonathan Gorard, Julia Dannemann-Freitag

  2. [2301.12611] - Perturbative Quantum Gravity Induced Scalar Coupling to Electromagnetism - S. Katuwal (U. Florida), R. P. Woodard (U. Florida)

  3. [2301.12170] - Semiclassical Einstein equations from holography and boundary dynamics - Akihiro Ishibashi, Kengo Maeda, Takashi Okamura

  4. [2301.12411] - The phase transition of Rastall AdS black hole with cloud of strings and quintessence - Mehdi Sadeghi, Faramarz Rahmani

  5. [2301.13029] - Determining the normalization of the quantum field theory vacuum, with implications for quantum gravity - Philip D. Mannheim

Mon - 01/30/23

Primordial black holes in loop quantum gravity: The effect on the threshold

  • Authors: Theodoros Papanikolaou
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
  • Arxiv link: https://arxiv.org/abs/2301.11439
  • Abstract Primordial black holes form in the early Universe and constitute one of the most viable candidates for dark matter. The study of their formation process requires the determination of a critical energy density perturbation threshold $\delta_\mathrm{c}$, which in general depends on the underlying gravity theory. Up to now, the majority of analytic and numerical techniques calculate $\delta_\mathrm{c}$ within the framework of general relativity. In this work, using simple physical arguments we estimate semi-analytically the PBH formation threshold within the framework of quantum gravity, working for concreteness within loop quantum gravity (LQG), which constitutes a non-perturbative and background-independent quantization of general relativity. In particular, for low mass PBHs formed close to the quantum bounce, we find a reduction in the value of $\delta_\mathrm{c}$ up to $50\%$ compared to the general relativistic regime quantifying for the first time to the best of our knowledge how quantum effects can influence PBH formation within a quantum gravity framework. Finally, by varying the Barbero-Immirzi parameter $\gamma$ of LQG we show its effect on the value of $\delta_\mathrm{c}$ while using the observational/phenomenological signatures associated to ultra-light PBHs, namely the ones affected by LQG effects, we propose the PBH portal as a novel probe to constrain the potential quantum nature of gravity.

There is no new related paper today

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