# 'Black universe' epoch in string cosmology

## Abstract

String theory compactification involves manifolds with multiple warp factors. For cosmological applications, we often introduce a short, high-energy inflationary throat, and a long, low-energy standard model (SM) throat. It is assumed that at the end of inflation, the excited Kaluza-Klein modes from the inflationary throat tunnel to the SM throat and reheat standard model degrees of freedom, which are attached to probe brane(s). However, the huge hierarchy of energy scales can result in a highly dynamic transition of the throat geometry. We point out that in such a cosmological scenario the standard model throat (together with SM brane) will be cloaked by a Schwarzschild horizon, produced by the Kaluza-Klein modes tunneling from the short throat. The black brane formation is dual to the first order chiral phase transition of the cascading gauge theory. We calculate the critical energy density corresponding the formation of the black hole (BH) horizon in the long throat. We discuss the duality between 'black universe' cosmology and an expanding universe driven by the hot gauge theory radiation. We address the new problem of the hierarchical multiple-throat scenarios: SM brane disappearance after the decay of the BH horizon.

- Authors:

- Department of Applied Mathematics, University of Western Ontario, London, Ontario, N6A 5B7 (Canada)
- (Canada)
- CITA, University of Toronto, 60 St. George Street, Toronto, Ontario, M5S 3H8 (Canada)

- Publication Date:

- OSTI Identifier:
- 21254496

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review. D, Particles Fields

- Additional Journal Information:
- Journal Volume: 78; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.78.086002; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BLACK HOLES; CHIRALITY; COMPACTIFICATION; COSMOLOGY; DECAY; DEGREES OF FREEDOM; DUALITY; ENERGY DENSITY; GAUGE INVARIANCE; INFLATION; KALUZA-KLEIN THEORY; PHASE TRANSFORMATIONS; STANDARD MODEL; STRING MODELS; TUNNEL EFFECT; UNIVERSE

### Citation Formats

```
Buchel, Alex, Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9, and Kofman, Lev.
```*'Black universe' epoch in string cosmology*. United States: N. p., 2008.
Web. doi:10.1103/PHYSREVD.78.086002.

```
Buchel, Alex, Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9, & Kofman, Lev.
```*'Black universe' epoch in string cosmology*. United States. doi:10.1103/PHYSREVD.78.086002.

```
Buchel, Alex, Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9, and Kofman, Lev. Wed .
"'Black universe' epoch in string cosmology". United States. doi:10.1103/PHYSREVD.78.086002.
```

```
@article{osti_21254496,
```

title = {'Black universe' epoch in string cosmology},

author = {Buchel, Alex and Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9 and Kofman, Lev},

abstractNote = {String theory compactification involves manifolds with multiple warp factors. For cosmological applications, we often introduce a short, high-energy inflationary throat, and a long, low-energy standard model (SM) throat. It is assumed that at the end of inflation, the excited Kaluza-Klein modes from the inflationary throat tunnel to the SM throat and reheat standard model degrees of freedom, which are attached to probe brane(s). However, the huge hierarchy of energy scales can result in a highly dynamic transition of the throat geometry. We point out that in such a cosmological scenario the standard model throat (together with SM brane) will be cloaked by a Schwarzschild horizon, produced by the Kaluza-Klein modes tunneling from the short throat. The black brane formation is dual to the first order chiral phase transition of the cascading gauge theory. We calculate the critical energy density corresponding the formation of the black hole (BH) horizon in the long throat. We discuss the duality between 'black universe' cosmology and an expanding universe driven by the hot gauge theory radiation. We address the new problem of the hierarchical multiple-throat scenarios: SM brane disappearance after the decay of the BH horizon.},

doi = {10.1103/PHYSREVD.78.086002},

journal = {Physical Review. D, Particles Fields},

issn = {0556-2821},

number = 8,

volume = 78,

place = {United States},

year = {2008},

month = {10}

}