A What are the frontiers of cosmology research?

[Avi Nandi]

I have completed post grad in Physics and in the transition phase between post grad and Ph.D. I am interested in cosmology and also completed a post grad course on Astrophysics and Cosmology. Can anyone enlighten me about what are the current debates and active topics of research going on in Cosmology?

 

[mathman]

I am not a cosmologists, but open topics I can see are: what is dark matter?, what can you say about dark energy?, how did the big bang start? - good luck!

 

[phinds]

Also, how do supermassive black holes form and what exactly IS the relationship between supermassive black holes and galaxy formation.

 

[kimbyd]

I have completed post grad in Physics and in the transition phase between post grad and Ph.D. I am interested in cosmology and also completed a post grad course on Astrophysics and Cosmology. Can anyone enlighten me about what are the current debates and active topics of research going on in Cosmology?

Here are a few that might be of interest, though it is by no means a comprehensive list:
1. Polarization of the CMB: while we now have a good handle on the temperature spectrum of the CMB, there is room to delve deeper into the polarization, especially the primordial B-mode polarization which may provide a window into inflation (if it is discovered). There are currently a number of balloon-borne and ground-based experiments ongoing. Eventually, there will hopefully be a new satellite experiment which is designed to measure polarization really well.
2. Gravitational waves. With LIGO detecting its first signals, there's a lot of excitement about gravitational wave astronomy. It may even be useful for measuring the expansion of the universe over time.
3. Structure formation. Understanding the dynamics of how galaxies and galaxy clusters form is an extraordinarily challenging problem, and there will be work to do in this area for many years to come. Work includes efforts on the modeling side in trying to calculate how these structures form, as well as on the observational side by making use of data from a wide array of telescopes from radio to x-ray. This potentially has implications for dark matter.
4. Modeling of the expansion and dynamics of the universe using large-scale surveys. This includes concepts such as Baryon Acoustic Oscillations, where the statistical properties of galaxies correlate to the imprint of sound waves visible on the CMB, allowing us to compare length scales of nearby structures to those of the CMB.

There are many others, but hopefully that gets you an idea of the kinds of things that many people in cosmology do.

 

[Chronos]

As kimbyd noted LIGO and large scale structure formation can be expected to dominate research over the next decade. CMB studies can also be expected to play an important role. The one big research project that hasn't been specifically mentioned is the dark energy survey - which will contribute greatly to our understanding of the nature and role of dark energy in the evolution of the universe. Also very exciting is the emergence of the next generation of telescopes, which will include some traditional ground based monsters plus very sophisticated spaceborne scopes. We are about to enter a truly golden age for astronomy in the very near future.This new generation of instruments will revolutionize our knowledge of the cosmos.

 

[alantheastronomer]

There are new radio telescope arrays that are looking for redshifted 21-cm neutral hydrogen emission from the earliest galaxies. While the really big question is: why was there an excess of matter left over from the era of annihilation between matter and antimatter in the early universe...this topic is being discussed on this forum in the post entitled "Antiparticles and Cosmology".

 

[kimbyd]

There are new radio telescope arrays that are looking for redshifted 21-cm neutral hydrogen emission from the earliest galaxies. While the really big question is: why was there an excess of matter left over from the era of annihilation between matter and antimatter in the early universe...this topic is being discussed on this forum in the post entitled "Antiparticles and Cosmology".

I don't know if that's the really big question. The matter/anti-matter imbalance is certainly a big question, though research in that area typically involves more high-energy physics than cosmology research.

 

[alantheastronomer]

I don't know if that's the really big question. The matter/anti-matter imbalance is certainly a big question, though research in that area typically involves more high-energy physics than cosmology research.

It is THE most fundamental question involving the origin of the Universe!

 

[kimbyd]

It is THE most fundamental question involving the origin of the Universe!

Eh. There are many such fundamental questions. What set up the initial density perturbations (inflation or something else?)? What is dark matter? Is the acceleration driven by a cosmological constant? Why are the symmetries obeyed by the Standard Model of particle physics SU(3)xSU(2)xU(1) instead of some other symmetries? How did those symmetries come about?

There's no way to say which is the most fundamental objectively. That's not an objective statement. I gather it's fundamental to you, but don't expect others to have the same opinion.

 

[alantheastronomer]

Eh. There are many such fundamental questions. What set up the initial density perturbations (inflation or something else?)? What is dark matter? Is the acceleration driven by a cosmological constant? Why are the symmetries obeyed by the Standard Model of particle physics SU(3)xSU(2)xU(1) instead of some other symmetries? How did those symmetries come about?

There's no way to say which is the most fundamental objectively. That's not an objective statement. I gather it's fundamental to you, but don't expect others to have the same opinion.

Yes those are also important questions as well, and they all should be considered by the op. Thank you for bringing them up!