Tangential large scale structure as a standard ruler: curvature parametersfrom quasars

Several observational analyses suggest that matter is spatially structured at a scale of L-LSS approximate to 130 h(-1) Mpc at low redshifts. This pea k in the power spectrum provides a standard ruler in comoving space which c an be used to compare the local geometry at high and low redshifts, thereby constraining the curvature parameters. It is shown here that this power spectrum peak is present in the observed q uasar distribution at z similar to 2: qualitatively, via wedge diagrams whi ch clearly show a void-like structure, and quantitatively, via one-dimensio nal Fourier analysis of the quasars' tangential distribution. The sample st udied here contains 812 quasars. The method produces strong constraints (68% confidence limits) on the densi ty parameter Ro and weaker constraints on the cosmological constant Xo, whi ch can be expressed by the relation Ohm(0) = (0.24+/-0.15)+(0. 10+/-0.08) l ambda(0). Independently of lambda(0) (in the range lambda(0) is an element of [0, 1]), the constraint is 0.1 < Ohm(0) < 0.45. Constraints if the cosmo logical constant is zero or if lambda(0) =1 - Ohm(0) are Ohm(0) = 0.24(-0.1 5)(+0.05) and Ohm(0) = 0.30 +/- 0.15 respectively. The power spectrum peak method is independent from the supernovae Type Ia m ethod by choice of astrophysical object, by redshift range, and by use of a standard ruler instead of a standard candle. Combination of the two result s yields Ohm(0) = (0.30 +/- 0.11) + (0.57 +/- 0.11)(lambda(0) - 0.7), 0.55 < lambda(0) < 0.95, (68% confidence limits) without assuming that lambda(0) = 1 - Ohm(0). This strongly supports the possibility that the observable u niverse satisfies a nearly flat, perturbed Friedmann-Lemaitre-Robertson-Wal ker model, independently of any cosmic microwave background observations. In other words it has been shown that Ohm(0) + lambda(0) = (1.0 +/- 0.11) (1.57 +/- 0.11)(lambda(0) - 0.7).