Inhomogeneous primordial nucleosynthesis and new abundance constraints on {Omega}{sub {ital bh}}{sup 2}

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Astrophysical Journal

DOI:https://doi.org/10.1086/176630· OSTI ID:283401

Mathews, G J ^[1]; Kajino, T; Orito, M ^[2]

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1. University of Notre Dame, Department of Physics, Notre Dame, Indiana 46635 (United States)
2. Division of Theoretical Astrophysics, National Astronomical Observatory, Mitaka, Tokyo 181 (Japan)

We discuss the upper limit to the baryonic contribution to the closure density. We consider effects of new observational and theoretical uncertainties in the primordial light-element abundances and the effects of fluctuation geometry on the inhomogeneous nucleosynthesis yields. We also consider implications of the possible detection of a high {ital D}/{ital H} abundance in a Lyman-{alpha} absorption cloud at high redshift and the implied chemical evolution effects of a high deuterium abundance. We show that there exists a region of the parameter space for inhomogeneous models in which a somewhat higher baryonic contribution to the closure density is possible than that allowed in standard homogeneous models. This result is contrary to some other recent studies and is due to both geometry and recently revised uncertainties in primordial light-element abundances, particularly {sup 7}Li. We find that the presently adopted abundance constraints are consistent with a contribution of baryons to the closure density as high as {Omega}{sub {ital bh{sup 2}}}{sub 50}{le}0.11 ({eta}{le}7{times}10{sup {minus}10}). This corresponds to a 20{percent} increase over the limit from standard homogeneous models ({Omega}{sub {ital bh{sup 2}}}{sub 50}{le}0.08, {eta}{le}5.8{times}10{sup {minus}10}). With a high deuterium abundance the upper limits for the inhomogeneous and homogeneous models would be {Omega}{sub {ital bh{sup 2}}}{sub 50}{le}0.04 and 0.03 ({eta}{le}2.6{times}10{sup {minus}10} and 1.9{times}10{sup {minus}10}), respectively. Even higher limits could be obtained by further relaxing the presently accepted primordial lithium abundance constraint as some have proposed. {copyright} {ital 1996 The American Astronomical Society.}

• DOE Contract Number: FG02-95ER40934
• OSTI ID: 283401
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 456; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BIG BANG
COSMOLOGICAL MODELS
DENSITY
DEUTERIUM
EARLY UNIVERSE
ELEMENT ABUNDANCE
HELIUM 3
INHOMOGENEITY
LIMITING VALUES
LITHIUM
LITHIUM 7
NONLUMINOUS MATTER
NUCLEOSYNTHESIS
UNIVERSE