*Post by giuseppe*could anybody tell me something about braneworld?

are there any good books or references you could give me?

There are at least two different research areas associated with the term

"brane world" which share some common ingredients but are rather disjoint,

as far as I am aware.

One of them is concerned with making cosmological models where some (our)

universe is modeled as the worldvolume of a p-brane (3-brane in particular)

which itself propagates in a higher-dimensional spacetime.

Reviews of this approach are for instance

Roy Maartens:

Brane-world gravity

http://arxiv.org/abs/gr-qc/0312059

E. Papantonopoulos:

Brane Cosmology

http://arxiv.org/abs/hep-th/0202044

and

David Langlois:

Brane cosmology: an introduction

http://arxiv.org/abs/hep-th/0209261

These brane world models are often (not always) more "string inspired" than

really string theoretic in that all they (often) really take as input from

string theory is the idea that there may be something like branes in the

first place.

I am not an expert on this stuff, but personally I find it interesting that

in these brane models it is rather natural to find realizations of the

inflaton field in terms of tachyonic string modes between brane/anti-brane

pairs or in terms of "radions" or other moduli. See for instance

Burgess, C. P.; Martineau, P.; Quevedo, F.; Rajesh, G.; Zhang, R. -J.:

Brane-Antibrane Inflation in Orbifold and Orientifold Models

http://arxiv.org/abs/hep-th/0111025

The inflaton and the Higgs field are the two famous tachyonic fields that

are postulated by our currently best ("standard") models of cosmology and

particle physics, without having been observed yet.

The other research area often associated with the word "brane world" is that

part of string phenomenology which tries to realize the standard model of

particel physics by studying compactifications of string theory with

intersecting D-branes in the compact dimensions. Since there are open

strings stretching between D-branes and since the low-energy effective field

theory of generated by these depends on the nature of these D-branes, one

can engineer a wide variety of standard-model-like effective field theories

by considering string backgrounds with suitable configurations of

intersecting D-branes.

Reviews for this topic are for instance

Ralph Blumenhagen, Mirjam Cvetic, Paul Langacker, Gary Shiu

Toward Realistic Intersecting D-Brane Models

http://arxiv.org/abs/hep-th/0502005

or

Fernando Marchesano:

Intersecting D-brane Models

http://arxiv.org/abs/hep-th/0307252 .

Here, too, it is interesting how the important tachyon, in this case the

Higgs, is realized in these models. See for instance

D. Cremades, L.E. Ibanez, F. Marchesano

Intersecting Brane Models of Particle Physics and the Higgs Mechanism

http://arxiv.org/abs/hep-th/0203160

Lubos has a while ago reviewed a recent paper on this topic

http://groups.google.de/group/sci.physics.strings/msg/45ffb6f2b0b3f8a6?hl=de