title: Implications of a primordial origin for the dispersion in D/H in quasar absorption systems.
abstract: We explore the difficulties with a primordial origin of variations of D/H in quasar absorption systems. In particular we examine options such as a very large-scale inhomogeneity in the baryon content of the universe. We show that very large-scale (much larger than 1 Mpc) isocurvature perturbations are excluded by current cosmic microwave background observations. Smaller-scale ad hoc perturbations (approximately 1 Mpc) still may lead to a large dispersion in primordial abundances but are subject to other constraints.
authors.affiliation: Case-Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7079, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Copi
authors.forename: K A
authors.initials: KA
authors.lastname: Olive
authors.forename: D N
authors.initials: DN
authors.lastname: Schramm