# Chameleonic strings and the cosmological constant problem

Andrea Zanzi (INFN, Florence)

18.04.2013 at 16:15

The chameleonic behaviour of the string theory dilaton and of matter fields is suggested. Some of the possible consequences of this scenario are analyzed. In particular, (1) I suggest a stringy solution to the cosmological constant problem and (2) I point out the non-equivalence of different conformal frames at the quantum level. The correct Dark Energy scale is recovered in the Einstein frame without unnatural fine-tunings and this result is robust against all quantum corrections, granted that we make some assumptions in the string frame of the model. At this stage the possibility still exists that a certain amount of fine-tuning may be required to satisfy phenomenological constraints. A detailed phenomenological analysis of the model is definitely necessary.

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