Abstract
Axions are produced during a period of dilaton-driven inflation by amplification of quantum fluctuations. We show that for some range of string cosmology parameters and some range of axion masses, primordial axions may constitute a large fraction of the present energy density in the universe in the form of cold dark matter. Due to the periodic nature of the axion potential energy density fluctuations are strongly suppressed. The spectrum of primordial axions is not thermal, allowing a small fraction of the axions to remain relativistic until quite late.
| Original language | English |
|---|---|
| Pages (from-to) | 74-81 |
| Number of pages | 8 |
| Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
| Volume | 442 |
| Issue number | 1-4 |
| DOIs | |
| State | Published - 3 Dec 1998 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank L. Kofman and G. Veneziano for useful comments, and M. Schwartz for helpful suggestions. This work is supported in part by the Israel Science Foundation administered by the Israel Academy of Sciences and Humanities.