String spectra near some null cosmological singularities

Journal Article · Mon Jun 15 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.126009· OSTI ID:21301046

Madhu, Kallingalthodi ^[1]; Narayan, K ^[2]

---

1. Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)
2. Chennai Mathematical Institute, SIPCOT IT Park, Padur PO, Siruseri 603103 (India)

We construct cosmological spacetimes with null Kasner-like singularities as purely gravitational solutions with no other background fields turned on. These can be recast as anisotropic plane-wave spacetimes by coordinate transformations. We analyze string quantization to find the spectrum of string modes in these backgrounds. The classical string modes can be solved for exactly in these time-dependent backgrounds, which enables a detailed study of the near-singularity string spectrum, (time-dependent) oscillator masses, and wave functions. We find that for low-lying string modes (finite oscillation number), the classical near-singularity string mode functions are nondivergent for various families of singularities. Furthermore, for any infinitesimal regularization of the vicinity of the singularity, we find a tower of string modes of ultrahigh oscillation number which propagate essentially freely in the background. The resulting picture suggests that string interactions are non-negligible near the singularity.

• OSTI ID: 21301046
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
EXACT SOLUTIONS
GRAVITATIONAL INTERACTIONS
INTERACTIONS
MASS
MATHEMATICAL SOLUTIONS
OSCILLATIONS
OSCILLATORS
QUANTIZATION
SINGULARITY
SPACE-TIME
SPECTRA
STRING MODELS
TIME DEPENDENCE
TRANSFORMATIONS
WAVE FUNCTIONS
WAVE PROPAGATION