In contrast with the classical gauge group cases, any method to prove exactly the scaling relation which relates moduli and prepotential is not known in the case of exceptional gauge groups. This paper provides a direct method to establish this relation by using Picard-Fuchs equations. In particular, it is shown that the scaling relation found by Ito in N = 2 supersymmetric G 2 Yang-Mills theor...

Picard-Vessiot rings are present in many settings like differential Galois theory, difference Galois theory and Galois theory of Artinian simple module algebras. In this article we set up an abstract framework in which we can prove theorems on existence and uniqueness of Picard-Vessiot rings, as well as on Galois groups corresponding to the Picard-Vessiot rings. As the present approach restrict...

A symbolic-numeric validation algorithm is developed to compute rigorous and tight uniform error bounds for polynomial approximate solutions linear ordinary differential equations, in particular D-finite functions. It relies on an a posteriori scheme, where such bound computed afterwards, independently from how the approximation was built. Contrary Newton–Galerkin methods, widely used mathemati...

Some existence and uniqueness theorems are established for weakly singular Volterra and Fredholm-Volterra integral equations in C[a, b]. Our method is based on fixed point theorems which are applied to the iterated operator and we apply the fiber Picard operator theorem to establish differentiability with respect to parameter. This method can be applied only for linear equations because otherwi...

We describe a strategy for computing Yukawa couplings and the mirror map, based on the Picard-Fuchs equation. (Our strategy is a variant of the method used by Candelas, de la Ossa, Green, and Parkes [5] in the case of quintic hypersurfaces.) We then explain a technique of Griffiths [14] which can be used to compute the Picard-Fuchs equations of hypersurfaces. Finally, we carry out the computati...

F is a differential field of characteristic zero with algebraically closed field of constants C. A Picard–Vessiot antiderivative closure of F is a differential field extension E ⊃ F which is a union of Picard–Vessiot extensions of F , each obtained by iterated adjunction of antiderivatives, and such that every such Picard– Vessiot extension of F has an isomorphic copy in E. The group G of diffe...

We prove some finiteness theorems for the Picard functor of an algebraic stack, in the spirit of SGA6, exp. XII and XIII. In particular, we give a stacky version of Raynaud’s relative representability theorem, we give sufficient conditions for the existence of the torsion component of the Picard functor, and for the finite generation of the Néron-Severi groups or of the Picard group itself. We ...

Frequentely it happens that isogenous (in the sense of Mukai) K3 surfaces are partners of each other and sometimes they are even isomorphic. This is due, in some cases, to the (too high, e.g. bigger then or equal to 12)) rank of the Picard lattice as showed by Mukai in [13]. In other cases this is due to the structure of the Picard lattice and not only on its rank. This is the case, for example...