Kerr-Schild geometry and string in general relativity.

Gürses, Metin


Harmonic mappings of Riemannian manifolds and Einstein field equations of gravitation.
Eriş, Ahmet; Nutku, Yavuz; Department of Physics (1976)
Causality in curved space
Aljasem Alashour, Bassem; Tekin, Bayram; Department of Physics (2018)
The notion of Causality is a key concept in formulating theories that describe real physical systems. So when a proposed model violates this concept this usually signals the existence of an error in the conceptual formulation or in the physical understanding of the results, which might indicate to us which models should we pursue, modify or drop all together. In this work the possibility of causality violations introduced by modifying Einstein gravity is studied using the idea of the time-delay introduced t...
Colliding gravitational waves in general relativity.
Halil, Mustafa; Nutku, Y.; Department of Physics (1977)
Second-order scalar-tensor field theories
Şahin, Ertan Sinan; Sarıoğlu, Bahtiyar Özgür; Department of Physics (2017)
We review Horndeski’s scalar-tensor theory in this thesis. Partial differential equations that are satisfied by the Lagrangian limit its most general form. Demanding second-order field equations both for the metric and the scalar field, and choosing a four-dimensional spacetime also put restrictions on the most general form of the Lagrangian. Besides, by using similar techniques, in a four-dimensional spacetime, we find the most general form of the second-order Euler-Lagrange equations that are obtained fro...
DUNDARER, A.Reşit (1993-03-01)
SO(8)+/- valued Yang-Mills multi-instantons are generalized to include three more winding numbers by parametrizing S8 = CP1+ X CP3 and performing the map x = (u,v1,v2,v3) --> w = (u(n),v1m1,v2m2,v3m3), so that the action is proportional to the product nm1m2m3. The fields that emerge in this parametrization form local representations of SO(8) at every point (v,m) of CP3 X (Z+)3 through the decomposition SO(8) = SO(8)/SO(7)XSO(7)/SO(6)XSO(6)/U(3)XU(3). Beside the duality relation F AND F = +/-*(F AND F), thes...
Citation Formats
M. Gürses, “Kerr-Schild geometry and string in general relativity.,” Ph.D. - Doctoral Program, Middle East Technical University, 1975.