The GUE Conjecture of Montgomery provides the first evidence in favor of the spectral interpretation of the non-trivial zeros of the Riemann zeta-function. Rather than being universally GUE, the Density Conjecture of Katz and Sarnak further associates a classical compact group to each reasonable family of L-function. In this thesis, we study the n-level density of the low-lying zeros of quadratic Dirichlet L-functions. Our results provide further support to the Density Conjecture. |