A nonsingular universe in string cosmology

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Al-Nowaiser A. A., Ozer M., Taha M. O.

INTERNATIONAL JOURNAL OF MODERN PHYSICS D, cilt.8, sa.1, ss.43-49, 1999 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 8 Sayı: 1
  • Basım Tarihi: 1999
  • Doi Numarası: 10.1142/s0218271899000055
  • Dergi Adı: INTERNATIONAL JOURNAL OF MODERN PHYSICS D
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.43-49
  • Yıldız Teknik Üniversitesi Adresli: Hayır

Özet

We consider the low-energy effective string action in four dimensions including the leading order-alpha' terms. An exact homogeneous solution is obtained. It represents a nonsingular expanding cosmological model in which the tensor fields tend to Vanish as t --> infinity. The scale factor a(t) of the very early universe in this model has the time dependence a(t)(2) = a(0)(2) + t(2). The violation of the strong energy condition of classical General Relativity to avoid the initial singularity requires that the central charge deficit of the theory be larger than a certain value. The significance of this solution is discussed.