Kinematics and dynamics of null hypersurfaces in the Einstein-Cartan spacetime and related thermodynamic interpretation

A general geometric construction of a generic null hypersurface in presence torsion the spacetime (Riemann-Cartan background), generated by vector ${l}^{a}$, is being developed here. We then explicitly define and structure various corresponding kinematical quantities. The dynamics surface, particularly given ${\stackrel{^}{G}}_{ab}{k}^{a}{l}^{b}$, also discussed. later one constructed under geodesic constraint condition. This yields relation among rate change expansion scalar to auxiliary ${k}^{a}$ entities on surface. Using this we show that Einstein-Cartan-Kibble-Sciama equation (which provides metric tensor) acquires thermodynamic interpretation. like temperature, entropy density, energy, pressure are properly identified. In whole analysis adopt geometrical field interpretation all discussions done covariant manner.