| Vol. 53,
No. 5 November 1999 pp. 833-841 Exact scalar field cosmologies in a higher derivative theory B C PAUL Physics Department, North
Bengal University, Siliguri, District Darjeeling 734 430,
India Abstract. We obtain exact cosmological solutions of a higher derivative theory described by the Lagrangian L = R + 2a R2 in the presence of interacting scalar field. The interacting scalar field potential required for a known evolution of the FRW universe in the framework of the theory is obtained using a technique different from the usual approach to solve the Einstein field equations. We follow here a technique to determine potential similar to that used by Ellis and Madsen in Einstein gravity. Some new and interesting potentials are noted in the presence of R2 term in the Einstein action for the known behaviours of the universe. These potentials in general do not obey the slow rollover approximation. Keywords. Cosmology; higher derivative theory. PACS Nos 04.20; 98.80 |