Article
Astronomy & Astrophysics
K. Narayan
Summary: We refine previous investigations on de Sitter space and extremal surfaces anchored at the future boundary I+. These surfaces require extra data or boundary conditions in the past and have real and positive areas, except for an overall -i factor relative to spacelike surfaces in AdS. By considering two aspects of time-entanglement in toy models, we find entirely positive structures in a future-past thermofield double type state and complex-valued entropy in the time evolution operator and reduced transition amplitudes.
Article
Physics, Multidisciplinary
Anxo Biasi, Oleg Evnin, Spyros Sypsas
Summary: Cosmological acceleration is difficult to explain in theories involving supergravity and superstrings, but it is possible in theories with regular black holes. By placing this scenario in a global antide Sitter background, the formation of de Sitter bubbles can be enhanced, potentially leading to the creation of multiple accelerating universes. Numerical work in a two-dimensional dilaton-gravity model supports this idea.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Sergio E. Aguilar-Gutierrez, Thomas Hertog, Rob Tielemans, Jan Pieter van der Schaar, Thomas Van Riet
Summary: This study investigates wormholes supported by axion flux, which have compact, one-handle structures. It reveals an upper bound on the axion flux and the suppression of wormholes compared to the round sphere. Additionally, the presence of the axion field leads to a reversal of the arrow of time through a quantum bounce.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Brayden R. Hull, Robert B. Mann
Summary: We demonstrate the existence of asymptotically de Sitter black holes of negative mass in Lovelock gravity. These black holes have horizon geometries with nonconstant curvature and are known as exotic black holes. We specifically study the case of Gauss-Bonnet gravity. We discuss the impact of transverse space geometry on the existence of black holes for both positive and negative mass solutions and provide closed form bounds for geometric parameters.
Article
Mathematics
S. Carolina Garcia-Martinez, Pascual Lucas, H. Fabian Ramirez-Ospina
Summary: In De Sitter space S-1(3) ? R-1(4) or anti de Sitter space H-1(3) ? R-2(4), for an orientable surface M-s(2) of L-1-2 type, the conditions of having constant principal curvature, constant mean curvature, and constant second mean curvature are equivalent. It is also shown that an L-1-2 type surface is either an open portion of a standard pseudo Riemannian product, or a B-scroll over a null curve, or has non-constant mean curvature, Gaussian curvature, and principal curvatures.
BULLETIN OF THE MALAYSIAN MATHEMATICAL SCIENCES SOCIETY
(2023)
Article
Astronomy & Astrophysics
Himanshu Gaur, Urjit A. Yajnik
Summary: In this paper, we investigate the relationship between entanglement and global internal symmetries in de Sitter space. By considering causally disconnected regions with symmetric properties, we examine the long range correlations in de Sitter space through studying the entanglement between these regions. We focus on the free complex scalar field and the free Dirac field on de Sitter space, both possessing global internal U(1) symmetry, and analyze the symmetry resolved entanglement entropy in the Bunch-Davies vacuum state. We find that the symmetry resolved entanglement entropy exhibits equipartition into local charge sectors up to terms of order O(1/VH3) in the limit of large VH3.
Article
Physics, Particles & Fields
Ben Pethybridge, Vladimir Schaub
Summary: In this paper, we construct the Wightman function for symmetric traceless tensors and Dirac fermions in dS(d+1) using a coordinate and index free formalism in a d + 2 dimensional ambient space. We expand this framework to cover spinor and tensor fields in any even or odd dimension. The goal is to provide a self-contained toolkit for studying fields of arbitrary spin in de Sitter, particularly in the context of cosmological perturbation theory.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Quantum Science & Technology
Shu-Min Wu, Hao-Sheng Zeng, Tonghua Liu
Summary: In this study, we investigate the influence of a two-mode Gaussian state under the Gaussian channel that describes the curvature effect in de Sitter space. Interestingly, the classical correlation may be unaffected by the curvature effect, while the quantum discord generally vanishes in the limit of infinite curvature. We also discover a useful monogamy relation for correlations between causally disconnected open charts, indicating that quantum discord and classical correlation can convert each other but the total correlation is conserved in de Sitter space.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Astronomy & Astrophysics
Chitraang Murdia, Yasunori Nomura, Kyle Ritchie
Summary: This article describes two different but equivalent semiclassical views, both of which can accommodate the equivalence principle and unitarity. In one view, unitarity is inherently built-in, while the black hole interior only emerges effectively as a collective phenomenon involving horizon (and possibly other) degrees of freedom. In the other, more widely studied approach, the existence of the interior is manifest, but the unitarity of the underlying dynamics can only be captured indirectly by incorporating certain nonperturbative effects of gravity. These two pictures correspond to a distant description and a description based on entanglement islands/replica wormholes, respectively. The existence of these two approaches is rooted in the two formulations of quantum mechanics: the canonical and path integral formalisms.
Article
Physics, Particles & Fields
Taishi Kawamoto, Shan-Ming Ruan, Yu-ki Suzuki, Tadashi Takayanagi
Summary: This work investigates the application of the holographic principle to cosmologies like de Sitter spacetime. By analyzing the holographic entanglement entropy in a half dS spacetime and comparing it with AdS/CFT, the study suggests that gravity on a half dSd+1 is dual to a highly non-local field theory residing on dSd boundary.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Mathematics, Applied
Ivan Dimitrijevic, Branko Dragovich, Zoran Rakic, Jelena Stankovic
Summary: In this paper, the authors further investigate the nonlocal de Sitter model of gravity and find an appropriate solution for the Schwarzschild-de Sitter metric. They successfully solve the equations of motion in a certain approximation. The obtained approximate solution is of particular interest for examining the possible role of non-local de Sitter gravity in describing the effects in galactic dynamics that are usually attributed to dark matter.
Article
Physics, Particles & Fields
A. F. Santos, S. C. Ulhoa, T. F. Furtado, Faqir C. Khanna
Summary: This paper explores the link between gravity and temperature, focusing on describing the physical mechanisms of various gravitational effects and discussing how temperature can impact de Sitter space-time. The effects of temperature are introduced using thermo field dynamics formalism, leading to the derivation of the gravitational Stefan-Boltzmann law. The discussion also covers the Unruh-type effect and gravitational Casimir effect in de Sitter space-time.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Laura Niermann, Tobias J. Osborne
Summary: Holographic tensor networks associated with tilings of (1 + 1)-dimensional de Sitter spacetime are introduced and their basic features are discussed. A comparison is made with conjectured properties of quantum gravity in de Sitter spacetime, highlighting the correspondence between the quantum information capacity of the network and the cosmological constant.
Article
Astronomy & Astrophysics
Llorenc Espinosa-Portales, Vincent Vennin
Summary: This study constructs Bell operators for quantum fields in real space and computes their expectation values for Gaussian states in terms of field power spectra. Applying the formalism to a scalar field in de-Sitter space-time, it is found that Bell inequalities are not violated in real space despite the generation of entangled particles on large scales. This is attributed to the implicit tracing over the field configurations at other locations, leading to effective decoherence and the erasure of quantum features.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Harry Goodhew
Summary: This paper proves that the wavefunction coefficients are rational based on a set of assumptions, and generalizes the manifestly local test to higher dimensions. This greatly reduces the allowed space of functions that wavefunction coefficients can take in both the Effective Field Theory of Inflation and Pure Gravity models, and is thus a key ingredient in the Cosmological Bootstrap program.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Particles & Fields
Bogdan Damski
Summary: In this paper, we discuss the dynamics of field configurations in the Proca theory of the real massive vector field, specifically focusing on a certain class of electric (magnetic) dipole-charged states. We construct these states to ensure that the long-distance structure of the mean electromagnetic field is initially set by the formula describing the electromagnetic field of the electric (magnetic) dipole. We analyze the evolution of this mean electromagnetic field over time and observe the phenomena of harmonic oscillations of the electric (magnetic) dipole moment far from the center of the initial field configuration, as well as the emergence of a spherical shock wave propagating at the speed of light near the center. Additionally, we discover a unique axisymmetric mean electric field configuration accompanying the mean magnetic field in magnetic dipole-charged states.
Article
Physics, Particles & Fields
Brett McInnes
Summary: The time-dependence of AdS black hole interior geometries poses challenges to holographic duality and the traversability of wormholes. Quantum circuit complexity of strongly coupled matter can address the first challenge. Data from a phenomenological model show an upper bound on the complexity growth rate, which becomes stricter with the addition of angular momentum. The slowing of black hole interior dynamics at high specific angular momentum also occurs.
Article
Physics, Particles & Fields
M. Beccaria, S. Giombi, A. A. Tseytlin
Summary: This article investigates the superconformal index Z of the 6d (2,0) theory on S5 x S1 and describes it using the quantum M2 brane theory in the large N limit. By studying M2 branes in a twisted product of thermal AdS7 and S4, the leading non-perturbative term at large N is shown to be reproduced by the 1-loop partition function of an instanton M2 brane wrapped on S1 x S2 with S2 c S4. Similarly, the partition function of a defect M2 brane wrapped on thermal AdS3 c AdS7 reproduces the BPS Wilson loop expectation value in the (2,0) theory. The article also comments on the analogy of these results with similar computations in the quantum M2 brane partition function in AdS4 x S7/DOUBLE-STRUCK CAPITAL Zk, which reproduced the corresponding localization expressions in the ABJM 3d gauge theory.
Article
Physics, Particles & Fields
Carlos Silva
Summary: This paper explores the nature of spacetime in quantum gravity based on a new version of the holographic principle that establishes a connection between string theory and polymer holonomy structures. The research findings suggest that, for this relationship to hold, spacetime must be perceived as emerging from a fundamental structure with degrees of freedom corresponding to quantum correlations only.
Article
Physics, Particles & Fields
A. Senol, H. Denizli, C. Helveci
Summary: This study investigates new physics using a Monte Carlo method, and the results show stronger limitations on anomalous quartic gauge couplings compared to previous experiments.