Mathematics – Number Theory
Scientific paper
2010-06-04
Mathematics
Number Theory
23 pages, final version
Scientific paper
Moduli spaces of stable coherent sheaves on a surface are of much interest for both mathematics and physics. Yoshioka computed generating functions of Poincare polynomials of such moduli spaces if the surface is the projective plane P2 and the rank of the sheaves is 2. Motivated by physical arguments, this paper investigates the modular properties of these generating functions. It is shown that these functions can be written in terms of the Lerch sum and theta function. Based on this, we prove a conjecture by Vafa and Witten, which expresses the generating functions of Euler numbers as a mixed mock modular form. Moreover, we derive an exact formula for the Fourier coefficients of this function, which is similar to the Rademacher expansion for weakly holomorphic modular forms but is more complicated. This is the first example of an exact formula for the Fourier coefficients of mixed mock modular forms, which is of independent mathematical interest.
Bringmann Kathrin
Manschot Jan
No associations
LandOfFree
From sheaves on P2 to a generalization of the Rademacher expansion does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with From sheaves on P2 to a generalization of the Rademacher expansion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and From sheaves on P2 to a generalization of the Rademacher expansion will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-723062