Screen transversal CR-lightlike submanifolds of indefinite cosymplectic manifolds

In this thesis, screen transversal Cauchy-Riemann (ST-CR) lightlike submanifolds of indefinite cosymplectic manifolds were introduced and the geometry of these submanifolds was investigated. The thesis was consisted of five chapters. In the first chapter and the second chapter, some information about the submanifolds theory was given, lightlike submanifolds were mentioned and studies in lightlike geometry were summarized. In the third chapter, the basic definitions and theorems which used in this thesis and taken place in the literature were presented. The fourth chapter is the original part of thesis and is divided into two sub-sections. In the first sub-section, the screen transversal CR-lightlike submanifolds of indefinite cosymplectic manifolds were described. Necessary and sufficient conditions for the induced connection of these submanifolds to be a metric connection were obtained and integrability of various distributions of submanifold was investigated. An important characterization theorem for such lightlike submanifolds of indefinite cosymplectic space forms was given. Later, conditions were obtained for screen transversal CR-lightlike submanifolds of indefinite cosymplectic manifolds to be screen transversal CR-lightlike product. In the second subsection, conditions were found for minimal screen transversal CR-lightlike submanifolds of indefinite cosymplectic manifolds. In the fifth section, the results and recommendations were presented.