Results 31 to 40 of about 66,341 (212)

Asymptotically safe — canonical quantum gravity junction

Journal of High Energy Physics
The canonical (CQG) and asymptotically safe (ASQG) approach to quantum gravity share to be both non-perturbative programmes. However, apart from that they seem to differ in several aspects such as: 1.
T. Thiemann
doaj   +1 more source

Intersecting Quantum Gravity with Noncommutative Geometry - a Review

Symmetry, Integrability and Geometry: Methods and Applications, 2012
We review applications of noncommutative geometry in canonical quantum gravity. First, we show that the framework of loop quantum gravity includes natural noncommutative structures which have, hitherto, not been explored.
Johannes Aastrup, Jesper Møller Grimstrup   +1 more
doaj   +1 more source

General relativity histories theory I: The spacetime character of the canonical description

, 2003
The problem of time in canonical quantum gravity is related to the fact that the canonical description is based on the prior choice of a spacelike foliation, hence making a reference to a spacetime metric.
Anastopoulos C, Arnowitt A, Ashtekar A, Dirac P A M, Gell-Mann M, Gell-Mann M, Griffiths R B, Hartle J B, Isham C, Isham C J, Isham C J, Isham C J, Isham C J, Kuchar K, Ntina Savvidou, Omnès R, Omnès R, Savvidou K, Savvidou K, Savvidou N, Savvidou N, Thiemann T   +21 more
core   +1 more source

Fully Integrated Silicone Electromagnetic Actuators for Untethered and Bio‐Inspired Soft Robotics

Advanced Intelligent Systems, EarlyView.
GA: A new class of soft electromagnetic actuators, with embedded coils and magnets, is here presented to enhance portability and usability outside structured environments. These actuators, fabricated through a custom additive manufacturing‐assisted process, offer high responsiveness, energy efficiency, and stretchability.
Antonio Pavone, Rosanna Rifino, Alessio Pricci, Gianni Stano, Gianluca Percoco   +4 more
wiley   +1 more source

A Multimode Soft Robot Based on a Single Braided Tube

Advanced Intelligent Systems, EarlyView.
This study introduces a novel soft multimode robot based on a single braided tube directly formed and actuated by SMA wires with distinct initial configurations. By combining contraction, elongation, and bending deformations, the robot achieves straight crawling, turning, inchworm crawling, and rolling without additional actuators.
Zhenhao Jia, Jiayao Ma, Yan Chen
wiley   +1 more source

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
doaj   +1 more source

On Spectral Triples in Quantum Gravity II

, 2008
A semifinite spectral triple for an algebra canonically associated to canonical quantum gravity is constructed. The algebra is generated by based loops in a triangulation and its barycentric subdivisions.
Aastrup J, Ashtekar A, Ashtekar A, Ashtekar A, Ashtekar A Lewandowski J, Baez J C, Barbero J F, Chamseddine A H Connes A, Chamseddine A H Connes A, Chamseddine A H Connes A, Chamseddine A H Connes A Marcolli M, Connes A, Connes A, Connes A, Henneaux M, Immirzi G, Jesper Møller Grimstrup, Johannes Aastrup, Loll R, Nicolai H, Orland P, Rennie A Varilly J C, Rovelli C, Ryszard Nest, Singer I M, Takesaki M, Thiemann T, Thiemann T   +27 more
core   +2 more sources

A Superalgebra Within: Representations of Lightest Standard Model Particles Form a Z25$\mathbb {Z}_2^5$‐Graded Algebra

Annalen der Physik, EarlyView.
 A set of particle representations, familiar from the Standard Model, collectively form a superalgebra. Those representations mirroring the behaviour of the Standard Model's gauge bosons, and three generations of fermions, are each included in this algebra, with exception only to those representations involving the top quark.
N. Furey
wiley   +1 more source

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
doaj   +1 more source

Three principles for canonical quantum gravity [PDF]

, 2012
We outline three principles that should guide us in the construction of a theory of canonical quantum gravity: 1) diffeomorphism invariance, 2) implementing the proper dynamics and related constraint algebra, 3) local Lorentz invariance.
Gambini, Rodolfo, Pullin, Jorge
core