Dilaton gravitasyon teorisinde bazı kesin karadelik ve çarpışan dalga çözümleri ve termodinamik özellikleri

We consider all possible theories in spherically symmetric Riemannian geometry in D-dimensions. We find solutions to such theories, in particu lar black hole solutions of the low energy limit of the string theory in D- dimensions and study their uniqueness. We find for the first time in litera ture, exact solutions of colliding Dilaton-Einstein-Maxwell Plane Waves. We investigate thermodynamical properties of four and five dimensional black hole solutions of toroidally compactified string theory. We find the explicit expression of the first law of black hole thermodynamics. We calculate the temperature T, angular velocity O and the electromagnetic potentials $; on the horizon using two different methods. Collision of plane waves in dilaton gravity theories and low energy limit of string theory is considered. The formulation of the problem and some exact solutions are presented Keywords : Gravitation, colliding waves, black holes, thermodynamics, spherical symmetry.