Physics 410/510 Observational Cosmology
Physics 410/510 On-line Access
How the Hell Did This Thing Get Here?
Modern Observational Cosmology
Instructor: Professor G. Bothun
- Office: 417 Willamette
- Hours: 10-12 M-F
- email: firstname.lastname@example.org
This class is designed to be an up to date summary of the last 10-20
years of observations relevant to Cosmology. During this period
several new kinds of theories and observations have come into existence
and our expectations of a simple and well-behaved large scale universe
are proving to be naieve. Also gone is our perception of a quiet
expanding local universe and a sensible large scale galaxy distribution.
Theory today is bombarded by a vast array of observational data but
there remains no clear and preferred model for the origin and evolution
of structure in the Universe. This will be the principal theme of the
course: to outline in understandable terms what the latest observations
are and how they are either consistent or in conflict with competeting
cosmogenic scenarios. In particular, we will focus on why structure
formation scenarios are largely inconsistent with the observations.
This is particularly evident when you look at
the power spectrum of the galaxy distribution .
Topics to be covered:
The order in which the following topics will be covered as not yet
been determined. That determination will be based on the background
level of the class convolved with student intrinsic in the following
- The Robertson Walker Metric and the Basic Cosmological Equations:
Within the context of General Relativity we need to define a framework
for specifying a geometrical model of the Universe that can
ultimately be determined by observations.
- Gravitational Instability; Euler's equations and the Jeans
instability criteria for a fluid -- This is the most mathematically
intensive portion of the class. This treatment defines the basic
idea of fluid instability in an expanding medium, caused by
density inhomogeneities. The growth of these perturbations has
produced, somehow, the structure that we see today.
- The Extragalactic Distance Scale - this is the procedure whereby
the expansion rate and expansion age of the Universe is determined.
This is central to all cosmological models. We use various properties
of galaxies to determine distances. This
doesn't really work all that well.
- Large Scale Structure -- The galaxy distribution is unbeleviably
clustered on a variety of size scales. Huge voids, great walls and
sheets and large clusters define a complex distrubution of matter which
currently is very poorly understood. As discussed above, the abundance
of structures seen is not understood in any theory whatsoever.
- The inflationary paradigm and the nature of the Dark Matter -
Inflation solves a lot of problems that are inherent in the standard
Big Bang Model. However, that model makes some specific predictions
the most significant of which is that the Universe must be entirely
dominated by Dark Matter whose nature is still, almost entirely unknown.
- Galaxy Formation and Evolution -
Ultimately galaxies serve as luminous probes of the Universe yet we
are very ignorant of how they formed and what their overall evolutionary
So if it seems like we don't know very much about Cosmology that would
be a correct inference. This course is about what we know and what we
don't know and the data which can be used to support or refute various
How this Class Works
- All material used in class will be available through the
course web pages. The lectures will set the context and go through
the derivations that are on the web pages.
- Sometimes the lectures will be delivered using computer projection
as the primary tool; other times the blackboard will be used.
- Student assignments will be based on data and simulations; some
of which are found at various web sites.
- There will be no midterms
- There will be several homework assignments given out throughout.
Some of these will require an in class oral report. These count for
40% of your grade.
- Students will do an intensive term project
which will account for
30% of your grade.
- There will be a comprehensive final exam which accounts for the
Internet Resources For This Class