The main research in cosmology is going in floowing areas:
1. Large scale structure of the universe:-
The main problems are
. Is universe really homogenious and isotroic ? ; I mean to find the scales above which
we can take universe to be homogeneious.
. How galaxy are formed ?
. What is the topology of universe ; this question is basically related to the size of universe.
. Most of the matter in universe is not visible it is dark . What it is dark matter.
. Do galaxy distribution is same as dark matter distribution ? (bias)
. From observation is has been proved that the expansion of the universe is accelerating ; there i is a mysterious energy that is responsible for it. What this energy (dark energy ) is ?
There are two main fields which are exploring few of these questions .
a) Galaxy survey :-
There are various groups which are measuring the distribution of galaxies in the universe.
These studies envolve measuring the positions of galaxies on sky and their redshift (which is a rough measure of radial distance ). These observations can be carried out in any wavelength but in general people use optical light.
SDSS : - It aims to measure the redshift and position sof about million galaxies
http://www.sdss.org/
2df survery : it also measure redshifts but its field if 2 degree.
http://www.aao.gov.au/2df/
Las campaness red**** survey
b) Gravitational N-body problems : - There are many groups that are exploiting computational power to model the structure formation in the univere. In these studies time evolution of millions of gravitating particles is studied.
One of the main groups is virgo consortium
http://www.virgo.dur.ac.uk/
2. Cosmic Microwave Bavkground Radiation :- CMBR is one of the main relics of early universe. I
it 's temperature distribution on the sky has been observed isotropicalup to a good accuracy, however, there are small anisotropies also. Today we see this CMBR sky as it was at the time when the radiation and matter was interacted last time. Anyway the CMBR sky contains a lot of information about the early universe.
NASA's WMAP project is one of the main projects that is involving in this
http://map.gsfc.nasa.gov/
3. Inflationary cosmology :-
It has been postulated that universe went a rapid period of expansion. This idea has solved many problems. Presently there is no unique model of inflation. So this also important to make this idea more prescise.
4. Supernova Ia : -
These are considered, there is project
http://panisse.lbl.gov/
This gives sufficient information about it.
5. Gravitational waves :
http://www.ligo.org/
6. Neutrino astronomy :
I will be back very soon