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. +1 more
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, 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 +25 more
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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.
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LRS Bianchi type-I cosmological model with constant deceleration parameter in $f(R,T)$ gravity
, 2017 A spatially homogeneous anisotropic LRS Bianchi type-I cosmological model is studied in $f(R,T)$ gravity with a special form of Hubble's parameter, which leads to constant deceleration parameter.
Bishi, Binaya K. +3 more
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Generating potentials via difference equations
, 2006 The condition for pressure isotropy, for spherically symmetric gravitational fields with charged and uncharged matter, is reduced to a recurrence equation with variable, rational coefficients.
Debnath +10 more
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Lagrange-Fedosov Nonholonomic Manifolds
, 2005 We outline an unified approach to geometrization of Lagrange mechanics, Finsler geometry and geometric methods of constructing exact solutions with generic off-diagonal terms and nonholonomic variables in gravity theories.
Barthel W. +28 more
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Isotropic universe with almost scale-invariant fourth-order gravity
, 2013 We study a broad class of isotropic vacuum cosmologies in fourth-order gravity under the condition that the gravitational Lagrangian be scale-invariant or almost scale-invariant. The gravitational Lagrangians considered will be of the form L = f(R) + k(G)
Schmidt, H. -J., Singleton, D.
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Exact Nonnull Wavelike Solutions to Gravity with Quadratic Lagrangians
, 1999 Solutions to gravity with quadratic Lagrangians are found for the simple case where the only nonconstant metric component is the lapse $N$ and the Riemann tensor takes the form $R^{t}_{.itj}=-k_{i}k_{j}, i,j=1,2,3$; thus these solutions depend on cross ...
Roberts, Mark D.
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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.
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