Counting solutions of a quadratic equation - LECTURE 2
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ABSTRACT: Let f be a given nonsingular quadratic form in n variables with
integer coefficients. Let m be a non-negative integer, either 0 or tending
to infinity. We are interested in giving an asymptotic formula for the
number of integer solutions of
f(x) = m
in a box PB, where the box B is fixed and the dilation factor P tends to
infinity. We make the convention that P is the square root of m, if m is
not 0. The first lecture describes the Hardy -Littlewood method and its
application to this problem when n is at least 5. Kloosterman's refinement
of the method is then descibed, with some background about Kloosterman
sums. This takes care of n = 4 and m positive.
In the second lecture the discussion shifts to Heath-Brown's version of
the circle method. The problem can now be tackled when m = 0 and n is
either 3 or 4. In the latter case, it makes a remarkable difference
whether or not the determinant of f is a square.
In conclusion, there is a short discussion of the approach to ternary
positive definite f that began with work of Iwaniec in 1986.
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LECTURE NOTES
The url of this page is http://qseries.org/fgarvan/quadformsconf/workshop-program/baker2.html.
Created by
F.G. Garvan
(fgarvan@math.ufl.edu) on
Saturday, February 28, 2009.
Last update made Sat Mar 7 20:21:47 EST 2009.
fgarvan@math.ufl.edu
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