Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singularity free dilaton-driven cosmologies and pre-little-bang   There are no reasons why the singularity in the growth of the dilaton
coupling should not be regularised, in a string cosmological context, by the
presence of classical inhomogeneities. We discuss a class of inhomogeneous
dilaton-driven models whose curvature invariants are all bounded and regular in
time and space. We prove that the non-space-like geodesics of these models are
all complete in the sense that none of them reaches infinity for a finite value
of the affine parameter. We conclude that our examples represent truly
singularity-free solutions of the low energy beta functions. We discuss some
symmetries of the obtained solutions and we clarify their physical
interpretation. We also give examples of solutions with spherical symmetry. In
our scenario each physical quantity is everywhere defined in time and space,
the big-bang singularity is replaced by a maximal curvature phase where the
dilaton kinetic energy reaches its maximum. The maximal curvature is always
smaller than one (in string units) and the coupling constant is also smaller
than one and it grows between two regimes of constant dilaton, implying,
together with the symmetries of the solutions, that higher genus and higher
curvature corrections are negligible. We argue that our examples describe, in a
string cosmological context, the occurrence of ``little bangs''(i.e. high
curvature phases which never develop physical singularities). They also suggest
the possibility of an unexplored ``pre-little-bang'' phase.

20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th