Results 81 to 90 of about 2,908,412 (339)

Viability of vector-tensor theories of gravity [PDF]

, 2008
We present a detailed study of the viability of general vector-tensor theories of gravity in the presence of an arbitrary temporal background vector field.
J. B. Jiménez, A. L. Maroto
semanticscholar   +1 more source

The cosmological constant as a boundary term

Journal of High Energy Physics, 2022
We compare the path integral for transition functions in unimodular gravity and in general relativity. In unimodular gravity the cosmological constant is a property of states that are specified at the boundaries whereas in general relativity the ...
Wilfried Buchmüller, Norbert Dragon
doaj   +1 more source

Topological M-theory as unification of form theories of gravity [PDF]

, 2004
We introduce a notion of topological M-theory and argue that it provides a unification of form theories of gravity in various dimensions. Its classical solutions involve G_2 holonomy metrics on 7-manifolds, obtained from a topological action for a 3-form
R. Dijkgraaf, S. Gukov, Andrew Neitzke, C. Vafa   +3 more
semanticscholar   +1 more source

Particle dynamics in a class of 2-dimensional gravity theories

, 1996
We provide a method to determine the motion of a classical massive particle in a background geometry of 2-dimensional gravity theories, for which the Birkhoff theorem holds.
A. Chamseddine, C. Teitelboim, C. Teitelboim, C.G. Callan, D. Louis-Martinez, D. Lowe, D.S. Hwang, Dae Sung Hwang, Dahl Park, G. Mandal, K. Isler, M. Henneux, O. Lechtenfeld, R. Jackiw, R.B. Mann, T. Banks, T. Fukuyama, Y. Kiem, Y. Kiem, Youngjai Kiem   +19 more
core   +2 more sources

Discrete structures in gravity [PDF]

, 2000
Discrete approaches to gravity, both classical and quantum, are reviewed briefly, with emphasis on the method using piecewise-linear spaces. Models of 3-dimensional quantum gravity involving 6j-symbols are then described, and progress in generalising ...
Ambjørn J., Archer F. J., Baez J., Baez J., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Birmingham D., Birmingham D., Brewin L., Brewin L., Carfora M., Caselle M., Correia da Silva C. L. B., Correia da Silva C. L. B., Franzosi R., Franzosi R., Freidel L., Freidel L., Gott J. R., Hamber H. W., Hamber H. W., Hartle J. B., Hasslacher B., Hollmann H. R., Immirzi G., Ionicioiu R., Ionicioiu R., Iwasaki J., Kauffman L. H., Mannion C. L., Markopoulou F., Markopoulou F., Menotti P., Ooguri H., Reisenberger M., Reisenberger M., Reisenberger M., Riedler J., Roberts J. D., Roček M., Ruth M. Williams, Schleich K., Schleich K., Tullio Regge, Turaev V. G., Waelbroeck H., Welling M., Williams R. M., ’t Hooft G., ’t Hooft G.   +54 more
core   +2 more sources

Non-relativistic geometry of holographic screens

Journal of High Energy Physics, 2017
We propose that the intrinsic geometry of holographic screens should be described by the Newton-Cartan geometry. As a test of this proposal, we show that the evolution equations of the screen can be written in a covariant form in terms of a stress tensor,
Mudassir Moosa
doaj   +1 more source

Rotating Liquid Marble Microreactors for Enhanced Enzymatic Reactions

Advanced Functional Materials, EarlyView.
Dynamic magnetic liquid marbles (LMs), stabilized by hydrophobic magnetic proteinaceous colloidosomes, function as effective microreactors for enzymatic processes. Precise magnetic manipulation allows for the rotation of these LMs, enhancing the efficiency of the enzymatic cascade reaction both at the air/water interface and within biphasic enzyme ...
Weijie Jiang, Xin Guan, Wei Liu, Yunxing Li, Hang Jiang, To Ngai   +5 more
wiley   +1 more source

Strong-coupled Relativity without Relativity

, 2002
GR can be interpreted as a theory of evolving 3-geometries. A recent such formulation, the 3-space approach of Barbour, Foster and \'{O} Murchadha, also permits the construction of a limited number of other theories of evolving 3-geometries, including ...
Anderson, Edward
core   +5 more sources

A new geometric flow on 3-manifolds: the K-flow

Journal of High Energy Physics, 2023
We define a new geometric flow, which we shall call the K-flow, on 3-dimensional Riemannian manifolds; and study the behavior of Thurston’s model geometries under this flow both analytically and numerically.
Kezban Tasseten, Bayram Tekin
doaj   +1 more source

3D Concrete Printing of Triply Periodic Minimum Surfaces for Enhanced Carbon Capture and Storage

Advanced Functional Materials, EarlyView.
A 3D‐printable and carbon‐capturing concrete is developed by replacing cement with diatomaceous earth (DE), which enhances rheology, provides hierarchical porosity, and serves as a nucleation site for carbonation. Maximum absorption of 488.7 gCO2 kgcement−1 is achieved in 7 days, a 142% increase over conventional concrete, and the triply periodic ...
Kun‐Hao Yu, Teng Teng, So Hee Nah, Hua Chai, Yefan Zhi, Kun‐Yu Wang, Yinding Chi, Peter Psarras, Masoud Akbarzadeh, Shu Yang   +9 more
wiley   +1 more source