Results 161 to 170 of about 173,760 (383)

Group field theories generating polyhedral complexes

, 2015
Group field theories are a generalization of matrix models which provide both a second quantized reformulation of loop quantum gravity as well as generating functions for spin foam models.
Thürigen, Johannes
core   +1 more source

Supercontinuum Generation in Soft Glass Photonic Crystal Fibers Developed Based on 3D Printed Preforms

Advanced Science, EarlyView.
This research investigates whether modern 3D glass printing can be used to develop advanced photonic crystal fibers suitable for supercontinuum generation. The team designs and fabricates a lead‐borate glass fiber with high nonlinearity, achieving an octave‐spanning spectrum in the mid‐infrared range.
Pawel Wienclaw, Przemyslaw Golebiewski, Grzegorz Stepniewski, Bartosz Paluba, Pawel Socha, Adam Filipkowski, Dariusz Pysz, Wenzhong Liu, Andrzej Burgs, Rafal Kasztelanic, Ryszard Buczynski   +10 more
wiley   +1 more source

Universal spacetimes in four dimensions

Journal of High Energy Physics, 2017
Universal spacetimes are exact solutions to all higher-order theories of gravity. We study these spacetimes in four dimensions and provide necessary and sufficient conditions for universality for all Petrov types except of type II.
S. Hervik, V. Pravda, A. Pravdová
doaj   +1 more source

Precision Measurement of the Position-space Wave Functions of Gravitationally Bound Ultracold Neutrons

, 2014
Gravity is the most familiar force at our natural length scale. However, it is still exotic from the view point of particle physics. The first experimental study of quantum effects under gravity was performed using a cold neutron beam in 1975.
Ichikawa, G., Kamiya, Y., Komamiya, S.
core   +2 more sources

Interface‐Adaptive Dual‐Color Hydrogel with Self‐Repairing Function and High Adhesion as Flexible Wearable Sensor for Minimally‐Invasive Monitoring Pesticide Residue in Living Crop

Advanced Science, EarlyView.
Dual‐color hydrogel TPE@Mn@ZnS@AG@PVA is prepared using b‐TPE NPs and r‐Mn@ZnS QDs as blue‐channel and red‐channel indicators, exhibits smart interface adaptability, high adhesion, good self‐repairing function, and superior response to thiophannate‐methyl, and thus acts as a flexible wearable sensor for in situ, on‐site and minimally‐destructive ...
Jianling Chen, Zihan Zhu, Yafei Li, Zizhe Wang, Wendong Wang, Hong Chen, Xuelian Xin, Zhenguo Chi, Haiyin Li   +8 more
wiley   +1 more source

Inequivalence of mimetic gravity with models of loop quantum gravity

Physical Review D
Certain versions of mimetic gravity have recently been claimed to present potential covariant theories of canonically modified spherically symmetric gravity, motivated by ingredients from loop quantum gravity. If such an equivalence were to hold, it would demonstrate general covariance of a large class of models considered in loop quantum gravity ...
Martin Bojowald, Erick I. Duque
openaire   +2 more sources

The (A)temporal Emergence of Spacetime [PDF]

, 2017
This paper examines two cosmological models of quantum gravity (from string theory and loop quantum gravity) to investigate the foundational and conceptual issues arising from quantum treatments of the big bang. While the classical singularity is erased,
Huggett, Nick, Wuthrich, Christian
core   +1 more source

A New Class of Group Field Theories for 1st Order Discrete Quantum Gravity

, 2007
Group Field Theories, a generalization of matrix models for 2d gravity, represent a 2nd quantization of both loop quantum gravity and simplicial quantum gravity.
Baez J C, Barrett J W, D Oriti, Engle J Pereira R Rovelli C, Freidel L, Freidel L, Freidel L Krasnov K, Freidel L Krasnov K Oriti D, Gelfand I M, Gradshteyn I S, Hamber H W, Hermann R, Livine E Speziale S, Oriti D, Oriti D, Oriti D, Oriti D, Perez A, Perez A Bojowald M, Reisenberger M, Rivers R J, Rovelli C, T Tlas, Williams R   +23 more
core   +1 more source

Water‐Wave Pancharatnam‐Berry Phase Induced by 4D Spin‐Orbit State Evolution

Advanced Science, EarlyView.
The first observation of the Pancharatnam‐Berry (PB) phase in water waves is reported, revealing its extraordinary properties including unbounded phase values, spin‐momentum‐locked unidirectional channels, and a Poincaré hypersphere representation. These findings demonstrate the universality of the PB phase across different wave systems and in higher ...
Wanyue Xiao, Shiqi Jia, Tong Fu, Shubo Wang   +3 more
wiley   +1 more source

Gravitational wavefunctions in JT supergravity

Journal of High Energy Physics
We determine explicit expressions for the continuous two-sided gravitational wavefunctions in supersymmetric versions of JT gravity, focusing mainly on N $$ \mathcal{N} $$ = 2 JT supergravity.
Andreas Belaey, Francesca Mariani, Thomas G. Mertens   +2 more
doaj   +1 more source