Ajnxtajnova teorija gravitacije uspexno opisuje pojave u Sunqevom
sistemu. Ona takodje predvia postojanje crnih rupa, gravitacionih sočiva
i gravitacionih talasa, xto je uspešno opservirano. Medjutim Ajnštajnova
teorija nije dovoljno proverena na velikim kosmičkim rastojanjima. Zbog toga
posmatramo nelokalnu modifikaciju gravitacije i dobijamo nova rešenja za
skalirajunje faktor a(t). Takodje, posmatramo i prostorno-vremenske pertur-
bacije de Siterovog prostora.Einstein theory of gravity successfully describes the Solar system. It
also predicts the existence of the black holes, gravitational lenses and gravitational
waves, which have been observed successfully. On the other hand Einstein theory of
gravity is not tested on the large cosmic sccale. Therefore, we consider the nonlocal
modied gravity and get new solutions for the cosmic scale factor a(t). Moreover
we consider space-time perturbations of the de Sitter space
