Probing the dark matter issue in f(R)-gravity via gravitational lensing

A few days ago in gr-qc  journal club we discussed an interesting paper by a member of our own institute, Probing the dark matter issue in f(R)-gravity via gravitational lensing.1. Background Dark Matter We theoretically expect dark matter to exist based largely on  extensive observations of both dynamics (rotation curves and objects such as the Read More …

Halos gone MAD

I have previously blogged about Structure finding in cosmological simulations and the Haloes Going Mad conference in Madrid this past spring–there you will find the basic background if you are unfamiliar with the subject and I’ll skip that in this post. The result of this conference was a Halo-finder comparison project and its findings were recent posted on the physics arxiv in the paper Haloes gone MAD: The Halo-Finder Comparison Project. I’ll summarize them here.

The paper concentrates on comparing codes on given test data, not comparing the results of various codes to observations, provides a standard test suite and proposes a standard methodology of comparison, both on test, isolated, halos and on a simulation of cosmological volume. Read More …