Quasar Lensing Statistics and Omega_Lambda: What Went Wrong?

Details Quasar Lensing Statistics and Omega_Lambda: What Went Wrong? Quasar Lensing Statistics and Omega_Lambda: What Went Wrong?

2005-01-23

arxiv.org/abs/astro-ph/0501491v1

Astronomy and Astrophysics

Astrophysics

To appear in "Impact of Gravitational Lensing on Cosmology", IAU Symposium 225, Eds. Y. Mellier and G. Meylan

Scientific paper

10.1017/S1743921305002231

In the pre-WMAP, pre-Supernova-Ia-Hubble-diagram era, quasar lensing statistics stubbornly indicated low values of Omega_Lambda. In contrast, a number of recent lensing statistics studies either find the data support the standard Lambda-CDM picture, or simply take the standard cosmological parameters as a given. Have the data or the analyses changed or improved, and how? I review several of the ``historical'' and the more recent studies, and show that there is no particular measurement, assumption, or model parameter in the old studies that was grossly wrong. Instead, at least several effects, operating together, are likely required in order to achieve agreement between the observations and the currently standard cosmology. Most likely among these effects are: a somewhat lower lensing cross section for elliptical galaxies than assumed in the past; some loss of lensed quasars in optical samples due to extinction by the lenses; and a somewhat lower-than-standard value of Omega_Lambda ~ 0.6. The agreement between recent model calculations and the results of radio lens surveys may be fortuitous, and due to a cancellation between the errors in the input parameters for the lens population and the cosmology, on the one hand, and for the source population, on the other hand.

Affiliated with

Also associated with

No associations

Rating

Quasar Lensing Statistics and Omega_Lambda: What Went Wrong? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quasar Lensing Statistics and Omega_Lambda: What Went Wrong?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quasar Lensing Statistics and Omega_Lambda: What Went Wrong? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-473197