Results 71 to 80 of about 47,027 (304)
Advances in Micro/Nanofiber‐Based Porous Materials for High‐Performance Thermal Insulation
Advanced Functional Materials, EarlyView.Micro/nanofiber porous materials have engendered great interest in the thermal insulation field. Herein, the structural designs, fabrication techniques, and applications of the micro/nanofiber thermal insulation materials are systematically summarized.
Xiaobao Gong +5 more
wiley +1 more source
Decorated tensor network renormalization for lattice gauge theories and spin foam models
New Journal of Physics, 2016 Tensor network techniques have proved to be powerful tools that can be employed to explore the large scale dynamics of lattice systems. Nonetheless, the redundancy of degrees of freedom in lattice gauge theories (and related models) poses a challenge for
Bianca Dittrich +2 more
doaj +1 more source
Gravity as BF theory plus potential
, 2009 Spin foam models of quantum gravity are based on Plebanski's formulation of general relativity as a constrained BF theory. We give an alternative formulation of gravity as BF theory plus a certain potential term for the B-field.
Krasnov, Kirill
core +1 more source
Testing the imposition of the spin foam simplicity constraints [PDF]
Classical and Quantum Gravity, 2012 We introduce a three-dimensional Plebanski action for the gauge group SO(4). In this model, the $B$ field satisfies quadratic simplicity constraints similar to that of the four-dimensional Plebanski theory, but with the difference that the $B$ field is now a one-form. We exhibit a natural notion of "simple one-form", and identify a gravitational sector,
Marc Geiller, Karim Noui, Karim Noui
openaire +5 more sources
Advanced Functional Materials, EarlyView.Controlling the polycrystallinity of CuO nanorods enables directional reconstruction into rod‐like structures that stabilize Cu(OH)2 and increase Cu+ ratios, while modulating interfacial water dynamics to enhance C─C coupling and boost C2+ product formation in CO2 electroreduction.
Hyeon‐Seok Bang +15 more
wiley +1 more source
Quantum group spin nets: refinement limit and relation to spin foams
, 2014 So far spin foam models are hardly understood beyond a few of their basic building blocks. To make progress on this question, we define analogue spin foam models, so called spin nets, for quantum groups $\text{SU}(2)_k$ and examine their effective ...
Dittrich, Bianca +2 more
core +1 more source
Spin foam models and the Duflo map
Classical and Quantum Gravity, 2019 Abstract We give a general definition of spin foam models, and then of models of 4d quantum gravity based on constraining BF theory. We highlight the construction and quantization ambiguities entering model building, among which the choice of quantization map applied to the B variables carrying metric information after imposing ...
Marco Finocchiaro +3 more
openaire +5 more sources
Advanced Functional Materials, EarlyView.Shellular materials form spontaneously by dip coating the primitive triply periodic minimal surface (TPMS) wireframe in an aqueous solution of lyotropic liquid crystalline graphene oxide (GO) nanosheets mixed with polymers. Regulated by surface tension, GO nanosheets align on the polymer soap film as the stress builds up during drying.
Yinding Chi +9 more
wiley +1 more source
Discrete Gravity Models and Loop Quantum Gravity: a Short Review
Symmetry, Integrability and Geometry: Methods and Applications, 2012 We review the relation between Loop Quantum Gravity on a fixed graph and discrete models of gravity. We compare Regge and twisted geometries, and discuss discrete actions based on twisted geometries and on the discretization of the Plebanski action.
Simone Speziale +2 more
doaj +1 more source
Demonstration of Focusing Wolter Mirrors for Neutron Phase and Magnetic Imaging
Journal of Imaging, 2018 Image-forming focusing mirrors were employed to demonstrate their applicability to two different modalities of neutron imaging, phase imaging with a far-field interferometer, and magnetic-field imaging through the manipulation of the neutron beam ...
Daniel S. Hussey +7 more
doaj +1 more source