Arguments based on thermodynamics and on the analysis of string creation effects in expanding spaces suggest the existence of an inflationary phase in the early universe for theories of closed strings. Einstein's equations on the other hand do not support such expectations. We solve this apparent paradox by noticing that Einstein's equations must be modified at the scale at which this inflationary phase takes place, so that the new equations satisfy the closed string duality principle. Inflation is natural in the context of such modifications and we give an estimate of the amount of inflation in this early epoch.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)