Resonances in One Dimension and Fredholm Determinants

We discuss resonances for Schrödinger operators in whole- and half-line problems. One of our goals is to connect the Fredholm determinant approach of Froese to the Fourier transform approach of Zworski. Another is to prove a result on the number of antibound states—namely, in a half-line problem there are an odd number of antibound states between any two bound states.