Compactification and signature transition in Kaluza-Klein spinor cosmology

Journal Article · Wed Nov 15 04:00:00 EST 2006 · Annals of Physics (New York)

DOI:https://doi.org/10.1016/j.aop.2006.04.016· OSTI ID:20845935

Vakili, B ^[1]; Jalalzadeh, S ^[1]; Sepangi, H R ^[2]

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1. Department of Physics, Shahid Beheshti University, Evin, Tehran 19839 (Iran, Islamic Republic of)
2. Department of Physics, Shahid Beheshti University, Evin, Tehran 19839 (Iran, Islamic Republic of) and Institute for Studies in Theoretical Physics and Mathematics, P.O. Box 19395-5746, Tehran (Iran, Islamic Republic of)

We study the classical and quantum cosmology of a 4 + 1-dimensional space-time with a non-zero cosmological constant coupled to a self-interacting massive spinor field. We consider a spatially flat Robertson-Walker universe with the usual scale factor R (t) and an internal scale factor a (t) associated with the extra dimension. For a free spinor field the resulting equations admit exact solutions, whereas for a self-interacting spinor field one should resort to a numerical method for exhibiting their behavior. These solutions give rise to a degenerate metric and exhibit signature transition from a Euclidean to a Lorentzian domain. Such transitions suggest a compactification mechanism for the internal and external scale factors such that a {approx} R {sup -1} in the Lorentzian region. The corresponding quantum cosmology and the ensuing Wheeler-DeWitt equation have exact solutions in the mini-superspace when the spinor field is free, leading to wavepackets undergoing signature change. The question of stabilization of the extra dimension is also discussed.

• OSTI ID: 20845935
• Journal Information: Annals of Physics (New York), Journal Name: Annals of Physics (New York) Journal Issue: 11 Vol. 321; ISSN 0003-4916; ISSN APNYA6
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPACTIFICATION
COSMOLOGICAL CONSTANT
COSMOLOGICAL MODELS
COSMOLOGY
EQUATIONS
EUCLIDEAN SPACE
EXACT SOLUTIONS
KALUZA-KLEIN THEORY
MANY-DIMENSIONAL CALCULATIONS
SPACE-TIME
SPINOR FIELDS
UNIVERSE
WAVE PACKETS