Diffusing nonlocal inflation: Solving the field equations as an initial value problem

作者：Mulryne D J^*; Nunes N J

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2008, 78(6): 063519.

DOI：10.1103/PhysRevD.78.063519

There has been considerable recent interest in solving nonlocal equations of motion which contain an infinite number of derivatives. Here, focusing on inflation, we review how the problem can be reformulated as the question of finding solutions to a diffusionlike partial differential equation with nonlinear boundary conditions. Moreover, we show that this diffusionlike equation, and hence the nonlocal equations, can be solved as an initial value problem once nontrivial initial data consistent with the boundary conditions is found. This is done by considering linearized equations about any field value, for which we show that obtaining solutions using the diffusionlike equation is equivalent to solving a local but infinite field cosmology. These local fields are shown to consist of at most two canonically normalized or phantom fields together with an infinite number of quintoms. We then numerically solve the diffusionlike equation for the full nonlinear case for two string field theory motivated models.

• 出版日期2008-9