Gravity’s Smoking Gun?
نویسندگان
چکیده
We present a new constraint on the biased galaxy formation picture. Gravitational instability theory predicts that the two-point mass density correlation function, ξ(r), has an inflection point at the separation r = ro, corresponding to the boundary between the linear and nonlinear regime of clustering, ξ ≃ 1. We show how this feature can be used to constrain the biasing parameter, b ≡ ξg(r)/ξ(r) on scales r ≃ ro, where ξg is the galaxy-galaxy correlation function, allowed to differ from ξ. We apply our method to real data: the ξg(r), estimated from the APM galaxy survey. Our results suggest that the APM galaxies trace the mass at separations r ∼> 5 h Mpc, where h is the Hubble constant in units of 100 km sMpc. The present results agree with earlier studies, based on comparing higher order correlations in the APM with weakly non-linear perturbation theory. Both approaches constrain the b factor to be within 20% of unity. If the existence of the feature we identified in the APM ξg(r) – the inflection point near ξg = 1 – is confirmed by more accurate surveys, we may have discovered gravity’s smoking gun: the long awaited “shoulder” in ξ, predicted by Gott and Rees 25 years ago. Subject headings: Cosmology – large-scale structure of universe
منابع مشابه
APM galaxies trace the mass: new evidence from gravitational dynamics
We present two new dynamical tests of the biasing hypothesis. The first is based on the amplitude and the shape of the galaxy-galaxy correlation function, ξg(r), where r is the separation of the galaxy pair. The second test uses the mean relative peculiar velocity for galaxy pairs, v12(r). This quantity is a measure of the rate of growth of clustering and it is related to the two-point correlat...
متن کاملThermodynamics of modified black holes from gravity’s rainbow
We study the thermodynamics of modified black holes proposed in the context of gravity’s rainbow. A notion of intrinsic temperature and entropy for these black holes is introduced. In particular for a specific class of modified Schwarzschild solutions, their temperature and entropy are obtained and compared with those previously obtained from modified dispersion relations in deformed special re...
متن کاملHMGB1: a smoking gun in lupus nephritis?
smoking gun is probably the most dramatic and iconic evidence of a crime. Th e concept of the smoking gun originated in a Sherlock Holmes story and then languished until it exploded into awareness during the impeachment hearings of Richard Nixon. As now understood , a smoking gun is an incontrovertible piece of evidence to establish a crime and even identify the perpetrator. Th is is especially...
متن کاملUnsupervised firearm handling by California adolescents.
OBJECTIVE Relatively little is known about the behavior of adolescents around firearms. The present investigation was undertaken to estimate the proportion of community-residing adolescents who report that they have ever handled a gun without adult knowledge or supervision. METHODS A random digit dial interview was conducted with 5801 California adolescents as part of the California Health In...
متن کامل