Recent observations have revealed that small-scale structure exists at high redshift. We study the possibility of the formation of such structure during baryogenesis and big bang nucleosynthesis. It is known that under certain conditions, high density baryonic bubbles are created in the Affleck-Dine model of baryogenesis, and these bubbles may occupy a relatively small fraction of space, while the dominant part of the cosmological volume is characterized by the normal observed baryon-to-photon ratio, η = 6·10-10. The value of η in the bubbles could be much larger than the usually accepted value (indeed, even close to unity) and still be consistent with the existing data on light element abundances and the observed angular spectrum of cosmic microwave background radiation (CMBR). We find upper bounds on η by comparing the abundances of heavy elements produced in big bang nucleosynthesis (BBN) and those of metal poor stars. We conclude that η should be smaller than 10-5 in some metal poor star regions.
Affleck-dine baryogenesis and heavy elements production from inhomogeneous big bang nucleosynthesis.
DOLGOV, Alexander;
2004
Abstract
Recent observations have revealed that small-scale structure exists at high redshift. We study the possibility of the formation of such structure during baryogenesis and big bang nucleosynthesis. It is known that under certain conditions, high density baryonic bubbles are created in the Affleck-Dine model of baryogenesis, and these bubbles may occupy a relatively small fraction of space, while the dominant part of the cosmological volume is characterized by the normal observed baryon-to-photon ratio, η = 6·10-10. The value of η in the bubbles could be much larger than the usually accepted value (indeed, even close to unity) and still be consistent with the existing data on light element abundances and the observed angular spectrum of cosmic microwave background radiation (CMBR). We find upper bounds on η by comparing the abundances of heavy elements produced in big bang nucleosynthesis (BBN) and those of metal poor stars. We conclude that η should be smaller than 10-5 in some metal poor star regions.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
