### Abstract

We study collision of two domain walls in five-dimensional (5D) spacetime and creation of matter fields. This may provide the reheating mechanism in cosmological models based on a colliding-brane scenario such as the ekpyrotic (or cyclic) universe. We first analyze the dynamics of colliding domain walls both in 5D Minkowski back-ground spacetime and in asymptotic AdS spacetime including self-gravity. We find that multiple bounces appear at collision. In the case with gravity, we find that a spacelike curvature singularity is formed in the bulk, but it is covered by a horizon. Next we analyze production of particles at collision of two domain walls. For a scalar field, the energy density of created particles is evaluated as ρ ≈ 20_{g} ^{-4}N_{b} m_{φ}
^{4} where ḡ is a coupling constant of particles to a domain-wall scalar field, N_{b} is the number of bounces at the collision and m_{φ} is a fundamental mass scale of the domain wall. We also study the behaviour of 5D fermions localized on domain walls, when two walls collide in a 5D Minkowski background spacetime. For k = 0 mode, we find that most fermions are localized on both branes as a whole even after collision. However, how much fermions are localized on which brane depends sensitively on the incident velocity and the coupling constants.

Original language | English |
---|---|

Pages (from-to) | 90-99 |

Number of pages | 10 |

Journal | Progress of Theoretical Physics Supplement |

Issue number | 172 |

Publication status | Published - 2008 |

### Fingerprint

### ASJC Scopus subject areas

- Physics and Astronomy (miscellaneous)

### Cite this

**Collision of domain walls and creation of matter in brane world.** / Maeda, Keiichi.

Research output: Contribution to journal › Article

*Progress of Theoretical Physics Supplement*, no. 172, pp. 90-99.

}

TY - JOUR

T1 - Collision of domain walls and creation of matter in brane world

AU - Maeda, Keiichi

PY - 2008

Y1 - 2008

N2 - We study collision of two domain walls in five-dimensional (5D) spacetime and creation of matter fields. This may provide the reheating mechanism in cosmological models based on a colliding-brane scenario such as the ekpyrotic (or cyclic) universe. We first analyze the dynamics of colliding domain walls both in 5D Minkowski back-ground spacetime and in asymptotic AdS spacetime including self-gravity. We find that multiple bounces appear at collision. In the case with gravity, we find that a spacelike curvature singularity is formed in the bulk, but it is covered by a horizon. Next we analyze production of particles at collision of two domain walls. For a scalar field, the energy density of created particles is evaluated as ρ ≈ 20g -4Nb mφ 4 where ḡ is a coupling constant of particles to a domain-wall scalar field, Nb is the number of bounces at the collision and mφ is a fundamental mass scale of the domain wall. We also study the behaviour of 5D fermions localized on domain walls, when two walls collide in a 5D Minkowski background spacetime. For k = 0 mode, we find that most fermions are localized on both branes as a whole even after collision. However, how much fermions are localized on which brane depends sensitively on the incident velocity and the coupling constants.

AB - We study collision of two domain walls in five-dimensional (5D) spacetime and creation of matter fields. This may provide the reheating mechanism in cosmological models based on a colliding-brane scenario such as the ekpyrotic (or cyclic) universe. We first analyze the dynamics of colliding domain walls both in 5D Minkowski back-ground spacetime and in asymptotic AdS spacetime including self-gravity. We find that multiple bounces appear at collision. In the case with gravity, we find that a spacelike curvature singularity is formed in the bulk, but it is covered by a horizon. Next we analyze production of particles at collision of two domain walls. For a scalar field, the energy density of created particles is evaluated as ρ ≈ 20g -4Nb mφ 4 where ḡ is a coupling constant of particles to a domain-wall scalar field, Nb is the number of bounces at the collision and mφ is a fundamental mass scale of the domain wall. We also study the behaviour of 5D fermions localized on domain walls, when two walls collide in a 5D Minkowski background spacetime. For k = 0 mode, we find that most fermions are localized on both branes as a whole even after collision. However, how much fermions are localized on which brane depends sensitively on the incident velocity and the coupling constants.

UR - http://www.scopus.com/inward/record.url?scp=52649097595&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=52649097595&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:52649097595

SP - 90

EP - 99

JO - Progress of Theoretical Physics

JF - Progress of Theoretical Physics

SN - 0033-068X

IS - 172

ER -