Introduction to Cosmology: Ph 444 Fall 2004
Lecturer Dr. Jerry Sellwood, room 308 in the Physics &
Astronomy Building, Busch Campus, telephone 445-5287,
Classes are Tues 4 & Thurs 4 in room 205 of the Allison Road Classroom
Building (ARC). I will declare an office hour on request, but I
prefer to keep it informal and to be available more or less any time.
Some notes for my lectures will be posted on this page shortly before
Solutions to homework: #1 and
Syllabus The topic of this course is one of the hottest
research topics in astronomy today. New data and ideas are emerging
all the time, although we now have a basic picture that is not
expected to require radical revision. (Statements like this have
always proved wrong in the past!) After a brief introduction and
overview, we will describe our current working picture, how it
emerged, what are the problems it faces, etc. Some topics which
we will dwell on in depth are:
- What is the geometry of the universe, is it closed, open or flat?
We will review modern evidence which strongly suggests the universe is
flat and possibly accelerating.
- What is the present rate of expansion of the universe? This will
involve a diversion into how we estimate distances to galaxies.
- What are the principal material constituents of the universe?
The stars and galaxies are made of familiar baryons (protons &
neutrons), but gravitational fields indicate much larger amounts of
"dark matter" which is generally assumed to be non-baryonic. We
will review the evidence for the existence of this material, and the
little that can be said about its properties.
- We will discuss the hot Big Bang, and how it gave rise to the
light elements and the cosmic microwave background.
- The simple Big Bang model has a number of problems which are
nicely accounted for by the modern idea of inflation.
- We will learn about the current favored model for the formation
of structure, which is known as the Cold Dark Matter model. If we
have time, we will learn about its successes and the difficulties it
Text I recommend Introduction to Cosmology by Barbara
Ryden, published by Addison Wesley as the text for this course. This
is a new book, which seems pretty good, and the course will follow it
reasonably closely. I will also assign homework from the book.
Assessment There will not be any exams. The homework will be
problems from the book (mostly), but I will also require a small
amount of computational work. I will require a term paper the end of
the semester on a topic of your choice from within the material of the
course, which you will also present to the class. With such a small
class, the lectures will be quite informal and I will try to encourage
discussion of the material. Participation in these discussions will
be part of the assessment.
Grades will be based on the term paper and presentation (40%),
homework (40%), and participation and attendance in class (20%).
The term paper should be on a topic closely related to the course.
The paper should explain why the selected topic is interesting and
should include your own assessement of the principal challenges
(observational or theoretical) facing your selected topic. It should
assume knowledge gained from the course, and cite and discuss papers
from the recent literature, going into more detail than in the
lectures. But it must be more than simply a summary of one or two
papers - I'd like to read what did, or did not, impress you about each
paper. Feel free to throw in an idea or two of your own as well.
I would prefer you to select your own topic, but I can suggest ideas
if you are stuck. You should let me know your topic by the end of
September. I may suggest that you narrow it down or broaden it, if
appropriate, and can suggest papers that you would find helpful.
The term paper will count 40% of your grade and will be assessed in
- (5%) A preliminary plan in note form (less than 1 page) is due on
October 14. It should list the main issues to be discussed in the
final paper and list some research and/or review papers that you think
- (25%) The written paper, which must be typewritten and
approximately 10 pages in length, is due on November 29 (the day after
- (10%) In the last few classes, you will each make a half hour
presentation of your paper to the rest of the class. The presentation
will be assessed: you should give a clear explanation of why the topic
is of interest, highlight the central few points of your term paper,
summarize the main uncertainties and criticisms, and finish within the
allotted time. There will be time for a short discussion after each
Astronomy on the web An enormous amount of astronomical
information is available on the web. This is a good
web page to start from for general astronomical information. There
are a couple of very useful search engines for articles from the
modern astronomical literature. All Journal articles are indexed, and
most are retrievable, from here.
Preprints in most branches of physics are posted here with those in astronomy on