Regge behavior saves string theory from causality violations
Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. . We analyze in detail this question by considering high-energy string-brane collisions at impact parameters b ≤ ls (the string-length parameter) with ls ≫ Rp (the characteristic scale of the Dp-brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector. Such violations are instead neatly avoided when the full structure of string theory — and in particular its Regge behavior — is taken into account.
KeywordsD-branes Bosonic Strings Models of Quantum Gravity
- G. D’Appollonio, P. Di Vecchia, R. Russo and G. Veneziano, A microscopic description of absorption in high-energy string-brane collisions, in preparation.Google Scholar