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Background material
All articles here will be linked to their arxiv.org version. Publication information
can usually be found from the arxiv posting.
Though somewhat out of date, Kip Thorne's article "Gravitational
radiation'' in the volume 300 Years of Gravitation is very much
worth knowing:
S. W. Hawking and W. Israel, editors, 300 Years of Gravitation
(Cambridge University Press, Cambridge, 1987), pp. 330 - 458.
A somewhat more up-to-date article (though already becoming rather
dated) is the following from the Proceedings of the 2001 Snowmass
Meeting. It covers material at roughly the same level as "300 years"
but not as comprehensively:
Cutler and Thorne's article is a bit more up to date, but focuses on
sources of waves:
Flanagan and Hughes give a pedagogical overview of GW calculation
(along with a somewhat sloppy updating/summary of topics covered in
the Snowmass article):
Thorne's überreview of multipole moments in GW physics. This
is the source of my lecture material on STF tensors:
Detectors, random processes, and noise
Much of the background material I presented on random processes and
the formalism from which things like the spectral density of a process
is defined is taken from a textbook in preparation that is being
written by Roger Blandford and Kip Thorne. The most up-to-date
version of the book I could find is available here; the
material on random processes is in Chapter 5.
The reference I mentioned on shot noise is this one:
The references I mentioned in class which discuss "quantum noise" are
these:
Close inspection reveals these papers to be the formalism which
was used to derive the so-called "standard quantum limit"; the limit
itself appears to be presented in a book. Bummer. For the highly
motivated, the book reference is
C. N. Caves, in Quantum Measurement and Chaos, ed. E. R. Pike,
Plenum: New York.
Sources
Two very nice articles for understanding how a primordial GW
background evolves as the universe expands (particularly through an
inflationary epoch):
B. Allen, The
stochastic gravity-wave background: sources and detection. Much
of the focus in on the regime relevant to detection by LIGO and
cousins, but there is very nice material on the background itself
and how to understand the manner in which it evolves.
T. Creighton, Gravitational waves and the
cosmological equation of state. Presents a beautiful little
calculation showing how the primordial spectrum is colored by the
epoch of expansion in which waves leave our Hubble volume and then
re-enter it. Never published for some odd reason (except on the
arxiv).
Section 9.4.3 of Thorne's article in 300 Years of Gravitation
is also very useful, modulo the out-of-datedness of some of the
astrophysical discussion.
The next topic we will discuss will be binary sources of gravitational
waves; in my (admittedly rather biased) opinion the most important of
the sources that we are currently searching for with exisiting and
planned detectors. A paper that came up in the lecture on primordial
gravitational waves is this one:
This very nice analysis examines the rate at which massive black hole
binaries which radiate in the band that pulsar timing attempts to
probe form and coalescence. It then discusses the spectrum of waves
we expect from such a population. Does a very nice job quantifying
the uncertainties in various assumptions.
Examples of similar but more recent work on massive black hole
binaries can be found here:
These works connect with the formation of such binaries to
hierarchical galaxy and structure growth models, generally predicting
fairly rates of binary black hole mergers, though with most mergers
typically happening at relatively high redshift.
The classic reference on extrapolating the observed population of
double neutron star binaries is
A similar analysis, focusing more on the demographics of the binaries
and how they form, is
Since these classics were published, the data has grown much richer,
as has our understanding of various systematic effects which make it
difficult to perform this extrapolation. Kalogera et al revisted
these calculations in 2001:
Having developed a decent model for the rate in the universe of such
events, one would like to use it to understanding issues in stellar
evolution and binary star populations, thereby making it possible to
model a wider range of compact binary phenomena. A nice recent
summary of some results in this regard is
One can also form binaries from stellar dynamics in dense star
clusters; such processes are known to produce x-ray binaries, which
eventually evolve into millisecond pulsars. (See for example this page with the 23
millisecond radio pulsars found in the globular cluster 47 Tucanae.)
Indeed, millisecond pulsars and low mass x-ray binaries are known to
overrepresented in globular clusters, pointing to the extremely
important role that dynamical processes play in these dense
environments.
Some critical background for understanding the details of this subject
can be found in Binney and Tremaine, Chapter 8:
J. Binney and S. Tremaine, Galactic Dynamics (Princeton
University Press, Princeton, 1987, Chapter 8.
An example of what one finds when a stellar population is evolved
through the dynamics of a globular cluster is this recent paper:
Finally, switching from binaries to individual objects, a very
comprehensive review of the different modes that can occur on objects
like neutron stars and black holes is given in
History
Our understanding of gravitational waves grew in fits and starts, not
at all in the smooth fashion that textbooks present it. That people
had the audacity, despite this, to think about measuring this
radiation is somewhat amazing. Daniel Kennefick has written up a very
nice history of some of the issues that had to be dealt with as people
tried to understand the backreaction of gravitational waves on an
emitter:
Students who get interested in this topic and would like to study this
a little more in-depth can borrow a copy of Dan's Ph.D. thesis from
me. Or, you can buy
his book.
Before going into science fiction writing, Bob Forward developed the
first wide-band interferometric gravitational-wave detector that was
used for long duration "observations." His (null) results were
published in 1977. (Note to students: Typos in the body of your paper
can be forgiven, but you should really try to get the
title right.)
Rai Weiss wrote an extremely influential and prescient article in 1972
which estimated the levels of noise that would likely characterize an
interferometric detector. Thanks to Tim Bodiya, we now have an
electronic version of this paper:
Rai Weiss, Gravitation research,
Quarterly Progress Report of the Research Laboratory of Electronics,
MIT (1972).
A more detailed version of this student was expanded into a study for
the NSF of the feasibility of making what eventually developed into
LIGO:
Damour's analysis which really laid to rest a lot of the formal
concerns over the validity of derivations of gravitational
backreaction is summarized in
Politics
Into each scientific life, some politics must fall. For those
interested in the sausage factory that is the politics of big
science
the
executive summary of the Beyond Einstein Program Assessment
Committee, and
the
full report, in a somewhat hard to read format. If I can figure
out a way to link a better version of the full report, I'll do so.
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