\item Prove that the quadratic form $q(x) = x_1^2 + x_2^2 - p (x_3^2 + x_4^2)$ does not represent zero, when $p=3$ or more generally when $p$ is a prime congruent to $3 \mod 4$.

Topics in Geometry and Dynamics

Math 275 - Harvard University
Syllabus and references
Notes on 3-manifolds!
Course notes
Discussion Group: Fridays, 12:30, 4th Floor Commons
Homework Essays

History of the ergodic theorem
Frequency of different decimal digits