COMMUNICATIONS IN NUMBER THEORY AND PHYSICS, vol.7, no.2, pp.327-359, 2013 (SCI-Expanded)
Let Y be a Calabi-Yau complete intersection in a weighted projective space. We show that the space of quadratic invariants of the hypergeometric group associated with the twisted I-function is one-dimensional, and spanned by the Gram matrix of a split-generator of the derived category of coherent sheaves on Y with respect to the Euler form.