The "almost" de Sitter expansion of current cosmological model implies a puzzle for SUSYsupersymmetry (SUSY) and also for string teeorytheory. A positive value of the cosmological constant implies a non-null vacuum energy that is, as far as I know, inconsistent with SUSY (SUSYwhich has to be broken in order to get a tiny -not huge!- cosmological constant. Moreover, interacting theories in de Sitter spacetimes are hard to handle in current string theory due to some issues concerning the S-matrix and that field strengths become imaginary in those spacetimes. My question is:
Is the currently accepted LCDM model of cosmology a challenge for SUSY/string theory? Wouldn't it be saying that SUSY and string theory are "wrong" or at least incomplete (or they will be, since we will approach a pure dS spacetime in the cosmological future it nothing changes)? Afterall, to my knowledge, de Sitter spacetimes are not well behaved in interacting field theories (andand thus, even in superstring M-theory!).
Remark: AdS/CFT is remarkably more "fit" to the SUSY/superstring idea, but it seems that the Universe has chosen the "wrong" sign for Lambda$\Lambda$!
