TY - JOUR
T1 - Inflation and dark energy arising from geometrical tachyons
AU - Panda, Sudhakar
AU - Sami, M.
AU - Tsujikawa, Shinji
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2006/1/15
Y1 - 2006/1/15
N2 - We study the motion of a Bogomolânyi-Prasad-Sommerfield D3-brane in the NS5-brane ring background. The radion field becomes tachyonic in this geometrical setup. We investigate the potential of this geometrical tachyon in the cosmological scenario for inflation as well as dark energy. We evaluate the spectra of scalar and tensor perturbations generated during tachyon inflation and show that this model is compatible with recent observations of cosmic microwave background due to an extra freedom of the number of NS5-branes. It is not possible to explain the origin of both inflation and dark energy by using a single tachyon field, since the energy density at the potential minimum is not negligibly small because of the amplitude of scalar perturbations set by cosmic microwave background anisotropies. However, the geometrical tachyon can account for dark energy when the number of NS5-branes is large, provided that inflation is realized by another scalar field.
AB - We study the motion of a Bogomolânyi-Prasad-Sommerfield D3-brane in the NS5-brane ring background. The radion field becomes tachyonic in this geometrical setup. We investigate the potential of this geometrical tachyon in the cosmological scenario for inflation as well as dark energy. We evaluate the spectra of scalar and tensor perturbations generated during tachyon inflation and show that this model is compatible with recent observations of cosmic microwave background due to an extra freedom of the number of NS5-branes. It is not possible to explain the origin of both inflation and dark energy by using a single tachyon field, since the energy density at the potential minimum is not negligibly small because of the amplitude of scalar perturbations set by cosmic microwave background anisotropies. However, the geometrical tachyon can account for dark energy when the number of NS5-branes is large, provided that inflation is realized by another scalar field.
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U2 - 10.1103/PhysRevD.73.023515
DO - 10.1103/PhysRevD.73.023515
M3 - Article
AN - SCOPUS:32644484886
VL - 73
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
SN - 1550-7998
IS - 2
M1 - 023515
ER -