Can Baryonic Features Produce the Observed 100 [CLC][ITAL]h[/ITAL][/CLC][TSUP]−1[/TSUP] M[CLC]pc[/CLC] Clustering?

We assess the possibility that baryonic acoustic oscillations in adiabaticmodels may explain the observations of excess power in large-scale structure on100h^-1 Mpc scales. The observed location restricts models to two extreme areasof parameter space. In either case, the baryon fraction must be large(Omega_b/Omega_0 > 0.3) to yield significant features. The first regionrequires Omega_0 < 0.2h to match the location, implying large blue tilts(n>1.4) to satisfy cluster abundance constraints. The power spectrum alsocontinues to rise toward larger scales in these models. The second regionrequires Omega_0 near 1, implying Omega_b well out of the range of big bangnucleosynthesis constraints; moreover, the peak is noticeably wider than theobservations suggest. Testable features of both solutions are that they requiremoderate reionization and thereby generate potentially observable (about 1 uK)large-angle polarization, as well as sub-arc-minute temperature fluctuations.In short, baryonic features in adiabatic models may explain the observed excessonly if currently favored determinations of cosmological parameters are insubstantial error or if present surveys do not represent a fair sample of100h^-1 Mpc structures.Comment: LaTeX, 7 pages, 5 Postscript figures, submitted to ApJ Letter