Brane Interaction as the Origin of Inflation

Abstract

We reanalyze brane inflation with brane-brane interactions at an angle, which include the special case of brane-anti-brane interaction. If nature is described by a stringy realization of the brane world scenario today (with arbitrary compactification), and if some additional branes were present in the early universe, we find that an inflationary epoch is generically quite natural, ending with a big bang when the last branes collide. In an interesting brane inflationary scenario suggested by generic string model-building, we use the density perturbation observed in the cosmic microwave background and the coupling unification to find that the string scale is comparable to the GU T scale.

Brane inflation revisited after WMAP five-year results

“…Nevertheless, the brane/antibrane inflation scenario inspired from string theory naturally indicates that cosmic strings would have a small contribution to the CMB, which is compatible with the observational limits [9,10,15]. This has led to a significant revival of all aspects of cosmic string scenario, including new theoretical motivations, phenomenological implications and direct observational searches, see e.g.…”

Inflation and String Theory

“…A renewed study of cosmic superstrings was initiated by Tye and collaborators in [595][596][597]. The essential new insight was that if the Standard Model arises on D-branes, the visible sector couplings and the string tension in Planck units can be adjusted independently, by changing the string 23 Most searches for cosmic string lensing involve extragalactic objects (cf.…”

“…[595]). The proposal of [695] was that weak supersymmetry breaking by a small angle θ 1 would diminish the Coulomb force to the extent that V int could drive slow-roll inflation.…”

Exact wave propagation in a spacetime with a cosmic string

“…If symmetry breaking occurred after inflation, the strings might survive until the present universe. Recently, cosmic strings attract a renewed interest partly because a variant of their formation mechanism was proposed in the context of the brane inflation scenario [18,19,20,21,22,23,24]. In this scenario inflation is driven by the attractive force between parallel Dbranes and parallel anti D-branes in a higher dimensional spacetime.…”