Results 61 to 70 of about 1,549,437 (171)
On Conformally Coupled General Relativity
EPJ Web of Conferences, 2018 A gravity model based on the conformal symmetry is presented. To specify the structure of the general coordinate transformations the Ogievetsky theorem is applied. The nonlinear symmetry realization approach is used.
Arbuzov Andrej, Latosh Boris
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On Propagation in Loop Quantum Gravity
Universe, 2022 A rigorous implementation of the Wheeler–Dewitt equations was derived in the context of Loop Quantum Gravity (LQG) and was coined Quantum Spin Dynamics (QSD). The Hamiltonian constraint of QSD was criticised as being too local and to prevent “propagation”
Thomas Thiemann, Madhavan Varadarajan
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One‐Shot Multimaterial 3D Printing of a Flexible Spine for a Robotic Fish Prototype
Advanced Intelligent Systems, Volume 8, Issue 8, August 2026.A one‐shot multimaterial 3D printing approach enables a monolithic soft robotic fish integrating a compliant spine and rigid vertebrae. Electromagnetic linear actuators drive tendon‐based transmission, producing controlled tail oscillations. Finite element modeling and experiments show strong agreement, while optimized material selection improves ...
Marco Colletta +3 more
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On the Emergence of Time in Quantum Gravity [PDF]
, 1999 We discuss from a philosophical perspective the way in which the normal concept of time might be said to `emerge' in a quantum theory of gravity. After an introduction, we briefly discuss the notion of emergence, without regard to time (Section 2).
Butterfield, Jeremy, Isham, Chris
core
Quantum astrometric observables II: time delay in linearized quantum gravity [PDF]
, 2013 A clock synchronization thought experiment is modeled by a diffeomorphism invariant "time delay" observable. In a sense, this observable probes the causal structure of the ambient Lorentzian spacetime. Thus, upon quantization, it is sensitive to the long
Sub String Theory Cosmology and ElemPart +8 more
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Journal of High Energy Physics, 2022 Motivated by the prospect of constraining microscopic models, we calculate the exact one-loop corrected de Sitter entropy (the logarithm of the sphere partition function) for every effective field theory of quantum gravity, with particles in arbitrary ...
Dionysios Anninos +3 more
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Micro-canonical and canonical description for generalised entropy
Physics Letters B, 2023 Few parameters dependent generalised entropy includes Tsallis entropy, Rényi entropy, Sharma-Mittal entropy, Barrow entropy, Kaniadakis entropy, etc as particular representatives. Its relation to physical systems is not always clear.
Shin'ichi Nojiri, Sergei D. Odintsov
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Direct Numerical Simulations of Inhalation in a 23‐Generation Lung Model
International Journal for Numerical Methods in Biomedical Engineering, Volume 42, Issue 8, August 2026.The first direct numerical simulation of a 23‐bifurcation lung model is carried out. Fast and intense oscillations in the laminar flow are found in deep generations: their time scales are related to the upstream pressure fluctuations, and their intensity is related to upstream flow‐splitting fluctuations.
Marco Atzori +4 more
wiley +1 more source
Nonperturbative solutions for canonical quantum gravity: An overview [PDF]
Physics Reports, 1997 In this paper we will make a survey of solutions to the Wheeler-Dewitt equation which have been found up to now in Ashtekar's formulation for canonical quantum gravity. Roughly speaking they are classified into two categories, namely, Wilson-loop solutions and topological solutions.
openaire +2 more sources
4D spherically symmetric time-dependent quantum gravity amplitudes
European Physical Journal C: Particles and FieldsIn these short notes, we compute non-perturbatively the time-dependent quantum gravity amplitudes for a four-dimensional spherically symmetric space-time with space-like and time-like boundaries.
J. A. Rosabal
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