Results 101 to 110 of about 2,908,412 (339)

Loop quantum gravity: the first twenty five years [PDF]

Classical and Quantum Gravity, 28 (2011) 153002, 2010
This is a review paper invited by the journal "Classical ad Quantum Gravity" for a "Cluster Issue" on approaches to quantum gravity. I give a synthetic presentation of loop gravity. I spell-out the aims of the theory and compare the results obtained with the initial hopes that motivated the early interest in this research direction.
arxiv   +1 more source

Exactly solvable charged dilaton gravity theories in two dimensions [PDF]

, 1998
We find exactly solvable dilaton gravity theories containing a U(1) gauge field in two dimensional space-time. The classical general solutions for the gravity sector (the metric plus the dilaton field) of the theories coupled to a massless complex scalar
Callan C G, Chang-Yeong Lee, Dahl Park, Horowitz G, Kiem Y, Kraus P, Maldacena J M, Mann R B, Youngjai Kiem   +8 more
core   +2 more sources

Kerr-Schild double copy for Kundt spacetimes of any dimension

Journal of High Energy Physics
We show that vacuum type N Kundt spacetimes in an arbitrary dimension admit a Kerr-Schild (KS) double copy. This is mostly done in a coordinate-independent way using the higher-dimensional Newman-Penrose formalism.
Marcello Ortaggio, Vojtěch Pravda, Alena Pravdová   +2 more
doaj   +1 more source

Higher order gravities and the Strong Equivalence Principle

Journal of High Energy Physics, 2017
We show that, in all metric theories of gravity with a general covariant action, gravity couples to the gravitational energy-momentum tensor in the same way it couples to the matter energy-momentum tensor order by order in the weak field approximation ...
Tomás Ortín
doaj   +1 more source

Mimicking Symmetry‐Breaking Einstein Ring by Optical Lens

Advanced Photonics Research, EarlyView.
This article uses an optical lens to emulate the gravitational lensing effect and observe the Einstein ring (ER) patterns. The symmetry‐breaking ER, i.e., Einstein cross, is observed utilizing a rotation‐symmetry‐breaking hemi‐ellipsoid lens. Deformed Einstein cross patterns induced by noncollinearly alignment of the light source–lens–observer are ...
Jun‐Liang Duan, Wen Xiao, Minyong Guo, Tong Liu, Huanyang Chen, Jin‐Hui Chen   +5 more
wiley   +1 more source

A note on classical and quantum unimodular gravity [PDF]

, 2014
We discuss unimodular gravity at a classical level, and in terms of its extension into the UV through an appropriate path integral representation. Classically, unimodular gravity is locally a gauge fixed version of general relativity (GR), and as such it
Antonio Padilla, I. Saltas
semanticscholar   +1 more source

Quantum Analysis of Jackiw and Teitelboim's Model for 1+1 D Gravity and Topological Gauge Theory [PDF]

Nucl.Phys. B395 (1993) 623-646, 1992
We study the BRST quantization of the 1+1 dimensional gravity model proposed by Jackiw and Teitelboim and also the topological gauge model which is equivalent to the gravity model at least classically. The gravity model quantized in the light-cone gauge is found to be a free theory with a nilpotent BRST charge. We show also that there exist twisted N=2
arxiv   +1 more source

Entropy Bound and Causality Violation in Higher Curvature Gravity

, 2008
In any quantum theory of gravity we do expect corrections to Einstein gravity to occur. Yet, at fundamental level, it is not apparent what the most relevant corrections are.
Anninos D Pastras G, Blau M, Charmousis C, Charmousis C Padilla A, Dadhich N, Dotti G, Dutta S, Ge X H Matsuo Y Shu F W Sin S J Tsukioka T, Henningson M, Ishwaree P Neupane, Kats Y Petrov P, Kofinas G, Kovtun P, Maeda H Nozawa M, Maldacena J M, Molina A Dadhich N, Molnar D, Myers R C Paulos M F Sinha A, Naresh Dadhich, Nojiri S, Sen A, Witten E   +21 more
core   +1 more source

Research Progress on Atmospheric Turbulence Perception and Correction Based on Adaptive Optics and Deep Learning

Advanced Photonics Research, EarlyView.
This work presents a systematic review of atmospheric turbulence fundamentals, including theoretical formulations and adaptive optics‐based mitigation strategies. This includes an in‐depth examination of the devices, theories, and methodologies associated with traditional correction approaches.
Qinghui Liu, Yihang Di, Mengmeng Zhang, Zhenbo Ren, Jianglei Di, Jianlin Zhao   +5 more
wiley   +1 more source

Integrable deformations of the AdS5×S5 superstring and the classical Yang-Baxter equation - Towards the gravity/CYBE correspondence - [PDF]

, 2014
Based on the formulation of Yang-Baxter sigma models developed by Klimcik and Delduc-Magro-Vicedo, we explain that various deformations of type IIB superstring on AdS5 × S5 can be charactered by classical r-matrices satisfying the classical Yang-Baxter ...
Takuya Matsumoto, Kentaroh Yoshida
semanticscholar   +1 more source