  In this paper we discuss the laws of thermodynamics for interacting tachyonic
scalar field. The components of the tachyonic scalar field in the universe are
taken to exist in the state of non-equilibrium initially, but due to
interaction they undergo a transition towards the equilibrium state. We show
that the zeroth law of thermodynamics demands interaction among the components
of cosmic field. The second law of thermodynamics is governing dynamics in
transfer of energy among the three components of the proposed field with local
violation of conservation of energy for individual components.
