Research Summary:

NEW: On Ice Ages and the Milky Way

(Updated September 2000)

This summary is also available in somewhat more concise versions: Postscript & PDF
For obvious reasons, the .pdf and .ps versions don't have movies in them!

Following are the different topics currently researched and links to more detailed descriptions.

The Structure of Super Eddington Atmospheres:

Detailed Description (with animated gifs and mpg movies)

Super Eddington Atmospheres do not blow themselves apart! Their secret is that as they approach the Eddington luminosity, they naturally become inhomogeneous (porous) and allow more radiation through without exerting as much force.

The Wind of Super Eddington Atmospheres:

Detailed Description

Super Eddington systems are known to exist and they have a natural explanation to their existence (see the aforementioned topic). However, they will generate a strong wind. The Luminosity - Mass Loss relation for these winds is predicted and compared to observed systems: The eruptions of classical novae and the great eruption of eta-Carinae 150 years ago.

Nonlinear Structure Formation at the time of recombination:

Detailed Description  (with mpg movies)

It is always assumed that the perturbations in the early universe at the time of recombination (which had Delta T / T of order 10-4 - 10-5) can be treated with a linear analysis. This isn't exactly true! It turns out that the strong radiation to gas pressure ratio can induce a nonlinear effect: Waves of order the acoustic horizon can amplify small scale waves (with M<106Msun). They grow exponentially. The number of e-folds they grow is linear with the amplitude of the large scale structure. Thus, the effect is very sensitive to the large scale amplitude and is found to be on the limit of being important.

Physics of light propagation through pulsar magnetospheres:

Detailed Description (with QuickTime and mpg movies)

Pulsar Magnetospheres are birefringent due to vacuum (QED) effects as well as plasma effects. This feature gives rise to various interesting effects. For example, the effective area that a magnetar will have in the two different polarizations is different, due to magnetic lensing!

The Screening of Nuclear Reactions in the Sun:

Detailed Description

Is there dynamic screening or is there not? That is the question. The screening corrections to reactions in the solar plasma are `measured' directly using a Molecular Dynamics simulation. The corrections affect the nuclear rates which in turn change the predicted solar nu fluxes.


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