Browsing by Author "Gürses, Metin"
Now showing items 1-20 of 29
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(2 + 1)-dimensional AKNS(−N) systems II
(Elsevier BV, 2021-06)In our previous work (Gürses and Pekcan, 2019, [40]) we started to investigate negative AKNS(−N) hierarchy in (2 + 1)-dimensions. We were able to obtain only the first three, N = 0, 1, 2, members of this hierarchy. The ... -
(2+1)-dimensional local and nonlocal reductions of the negative AKNS system: soliton solutions
(Elsevier, 2018)Wefirstconstructa(2+1)dimensionalnegativeAKNShierarchyandthenwegiveallpossiblelocaland(discrete)nonlocalreductionsoftheseequations.WefindHirotabilinearformsofthenegativeAKNShierarchyandgiveone-andtwo-solitonsolutions.Byu ... -
Classical double copy: Kerr-Schild-Kundt metrics from Yang-Mills theory
(American Physical Society, 2018)The classical double copy idea relates some solutions of Einstein's theory with those of gauge and scalar field theories. We study the Kerr-Schild-Kundt (KSK) class of metrics in d dimensions in the context of possible new ... -
Comment on “Einstein-Gauss-Bonnet Gravity in four-dimensional spacetime”
(American Physical Society, 2020)We summarize our proof that the "Einstein-Gauss-Bonnet Gravity in Four-Dimensional Spacetime" introduced in Phys. Rev. Lett. 124, 081301 (2020) does not have consistent field equations, as such the theory does not exist. ... -
Discrete symmetries and nonlocal reductions
(Elsevier, 2020)We show that nonlocal reductions of systems of integrable nonlinear partial differential equations are the special discrete symmetry transformations. -
Extremely charged static dust distributions in general relativity
(World Scientific, 1998)Conformo static charged dust distributions are investigated in the framework of general relativity. Einstein’s equations reduce to a non-linear version of Poisson’s equation and Maxwell’s equations imply the equality of ... -
FLRW-cosmology in generic gravity theories
(Springer Science and Business Media Deutschland GmbH, 2020-11)We prove that for the Friedmann–Lemaitre–Robertson–Walker metric, the field equations of any generic gravity theory in arbitrary dimensions are of the perfect fluid type. The cases of general Lovelock and F(R,G)F(R,G) ... -
Integrable nonlocal reductions
(Springer New York LLC, 2018)We present some nonlocal integrable systems by using the Ablowitz-Musslimani nonlocal reductions. We first present all possible nonlocal reductions of nonlinear Schrödinger (NLS) and modified Korteweg-de Vries (mKdV) ... -
Is there a novel Einstein–Gauss–Bonnet theory in four dimensions?
(Springer, 2020-07)No! We show that the field equations of Einstein–Gauss–Bonnet theory defined in generic D>4D>4 dimensions split into two parts one of which always remains higher dimensional, and hence the theory does not have a non-trivial ... -
Kerr-Schild-Kundt metrics in generic Einstein-Maxwell theories
(American Physical Society, 2022-02-03)We study the Kerr-Schild-Kundt class of metrics in generic gravity theories with Maxwell’s field. We prove that these metrics linearize and simplify the field equations of generic gravity theories with Maxwell’s field. -
Kerr–Schild–Kundt metrics in generic gravity theories with modified Horndeski couplings
(Springer, 2021-12-31)The Kerr–Schild–Kundt (KSK) metrics are known to be one of the universal metrics in general relativity, which means that they solve the vacuum field equations of any gravity theory constructed from the curvature tensor and ... -
A Modified Gravity Theory: Null Aether*
(Chinese Physical Society and IOP Publishing, 2019-03)General quantum gravity arguments predict that Lorentz symmetry might not hold exactly in nature. This has motivated much interest in Lorentz breaking gravity theories recently. Among such models are vector-tensor theories ... -
Motion of curves on two-dimensional surfaces and soliton equations
(Elsevier BV * North - Holland, 1998)A connection is established between the soliton equations and curves moving in a three-dimensional space V3. The signs of the self-interacting terms of the soliton equations are related to the signature of V3. It is shown ... -
NAT black holes
(Springer, 2019)We study some physical properties of black holes in Null Aether Theory (NAT) – a vector-tensor theory of gravity. We first review the black hole solutions in NAT and then derive the first law of black hole thermodynamics. ... -
New classes of spherically symmetric, inhomogeneous cosmological models
(American Physical Society, 2019)We present two classes of inhomogeneous, spherically symmetric solutions of the Einstein-Maxwell-perfect fluid field equations with cosmological constant generalizing the Vaidya-Shah solution. Some special limits of our ... -
New symmetries of the vacuum Einstein equations
(American Physical Society, 1993)Some new symmetry algebras are found for the vacuum Einstein equations. Among them there exists an infinite-dimensional algebra representing the symmetries analogous to the generalized symmetries of the integrable nonlinear ... -
Non-Einsteinian black holes in generic 3D gravity theories
(American Physical Society, 2019)The Bañados-Teitelboim-Zanelli (BTZ) black hole metric solves the three-dimensional Einstein’s theory with a negative cosmological constant as well as all the generic higher derivative gravity theories based on the metric; ... -
Nonlocal Fordy-Kulish equations on symmetric spaces
(Elsevier, 2017)We present nonlocal integrable reductions of the Fordy–Kulish system of nonlinear Schrodinger equations and the Fordy system of derivative nonlinear Schrodinger equations on Hermitian symmetric spaces. Examples are given ... -
Nonlocal hydrodynamic type of equations
(Elsevier, 2020-03-01)We show that the integrable equations of hydrodynamic type admit nonlocal reductions. We first construct such reductions for a general Lax equation and then give several examples. The reduced nonlocal equations are of ... -
Nonlocal KdV equations
(Elsevier, 2020)Writing the Hirota-Satsuma (HS) system of equations in a symmetrical form we find its local and new nonlocal reductions. It turns out that all reductions of the HS system are Korteweg-de Vries (KdV), complex KdV, and new ...
