Results 31 to 39 of about 202 (39)

New anisotropic models from isotropic solutions

, 2005
We establish an algorithm that produces a new solution to the Einstein field equations, with an anisotropic matter distribution, from a given seed isotropic solution.
Bowers, Chaisi, Chaisi, Dev, Dev, Gokhroo, Herrera, Herrera, Ivanov, Maharaj, Maharaj, Mak, Mak, Rhoades, Saslaw, Saslaw, Sharma, Stephani, Wolfram   +18 more
core   +2 more sources

Fractional Curve Flows and Solitonic Hierarchies in Gravity and Geometric Mechanics

, 2011
Methods from the geometry of nonholonomic manifolds and Lagrange-Finsler spaces are applied in fractional calculus with Caputo derivatives and for elaborating models of fractional gravity and fractional Lagrange mechanics.
Dumitru Baleanu, Gorenflo R., Kilbas A. A., Sergiu I. Vacaru   +3 more
core   +1 more source

Partner symmetries of the complex Monge-Ampere equation yield hyper-Kahler metrics without continuous symmetries

, 2003
We extend the Mason-Newman Lax pair for the elliptic complex Monge-Amp\`ere equation so that this equation itself emerges as an algebraic consequence. We regard the function in the extended Lax equations as a complex potential.
A A Malykh, Aliev A N, Atiyah M, Atiyah M F, Bluman G W, Boyer C P, Dunajskii M, Dunajskii M, Goldblatt E, Hitchin N J, Lechtenfeld O, Lie S, M B Sheftel, Malykh A A, Malykh A A, Malykh A A, Martina L, Mason L J, Mason L J, Nutku Y, Nutku Y, Olver P, Ovsiannikov L V, Popov A D, Vessiot E, Y Nutku   +25 more
core   +1 more source

Dark energy in spherically symmetric universe coupled with Brans-Dicke scalar field

, 2019
The phenomenon of dark energy and its manifestations are studied in a spherically symmetric universe considering the Brans-Dicke scalar tensor theory. In the first model the dark energy behaves like a phantom type and in such a universe the existence of ...
Samanta, Gauranga C., Singh, Koijam Manihar   +1 more
core   +1 more source

On conformally recurrent manifolds of dimension greater than 4

, 2016
Conformally recurrent pseudo-Riemannian manifolds of dimension n>4 are investigated. The Weyl tensor is represented as a Kulkarni-Nomizu product. If the square of the Weyl tensor is nonzero, a covariantly constant symmetric tensor is constructed, that is
Mantica, Carlo A., Molinari, Luca G.
core   +1 more source

Penrose junction conditions with Λ : geometric insights into low-regularity metrics for impulsive gravitational waves. [PDF]

Gen Relativ Gravit, 2022
Podolský J, Steinbauer R.
europepmc   +1 more source

Analysis of transmission dynamics of COVID-19 via closed-form solutions of a susceptible-infectious-quarantined-diseased model with a quarantine-adjusted incidence function. [PDF]

Math Methods Appl Sci, 2021
Naz R, Al-Raeei M.
europepmc   +1 more source

Complete classification of spatial surfaces with parallel mean curvature vector in arbitrary non-flat pseudo-Riemannian space forms

Open Mathematics, 2009
Chen Bang-Yen
doaj   +1 more source

Cut-and-paste for impulsive gravitational waves with Λ: the mathematical analysis. [PDF]

Lett Math Phys
Sämann C, Schinnerl B, Steinbauer R, Švarc R.   +3 more
europepmc   +1 more source