May 26, 2005

May 26

Ben Freivogel, Matthew Kleban, Maria Rodriguez Martinez, and Leonard Susskind have written a paper Observational Consequences of a Landscape.

They write: "The string theory landscape of metastable de Sitter vacua is extremely rich. So many vacua exist that the large numbers can compensate the apparent fine-tuning of the cosmological constant, the gauge hierarchy, and whatever additional fine-tunings are phenomenologically required by observational data. Specifically we assume a large set S of minima consistent with the standard model and the small measured cosmological constant."

They squeeze out a number 10% that the actual number of efolds is between 62 and 64 with the observed bound being 62. Their opinion is that the observed suppression of the quadrupole and octopole anisotropies, seen by WMAP, should not be quickly dismissed as cosmic variance accidents.

It seems that the scientific and anthropic landscape paradigm string theory camps are drifting apart. Does one or the other (or both) have some of the fundamentals wrong? Do we have to be prepared to reevaluate where the limits of human scientific knowledge are.