1112.3341 (Raphael Bousso)
Raphael Bousso
We find ourselves in an extended era of entropy production. Unlike most other
observations, the arrow of time is usually regarded as a constraint on initial
conditions. I argue, however, that it primarily constrains the vacuum structure
of the theory. I exhibit simple scalar field potentials in which low-entropy
initial conditions are not necessary, or not sufficient, for an arrow of time
to arise. I argue that the string theory landscape gives rise to an arrow of
time independently of the initial entropy, assuming a plausible condition on
the lifetime of its metastable vacua. In particular, a theory of initial
conditions that favors large initial entropy, such as the Hartle-Hawking
proposal, is not ruled out by observation. The dynamical resolution of the
arrow of time problem arises from the same structural properties of the string
landscape that allow it to solve the cosmological constant problem without
producing an empty universe, particularly its high dimensionality and the large
difference in vacuum energy between neighboring vacua.
View original:
http://arxiv.org/abs/1112.3341
No comments:
Post a Comment