Fundamental pair of periodsIn mathematics, a fundamental pair of periods is an ordered pair of complex numbers that defines a lattice in the complex plane. This type of lattice is the underlying object with which elliptic functions and modular forms are defined. A fundamental pair of periods is a pair of complex numbers such that their ratio is not real. If considered as vectors in , the two are not collinear. The lattice generated by and is This lattice is also sometimes denoted as to make clear that it depends on and It is also sometimes denoted by or or simply by The two generators and are called the lattice basis.
Intersection numberIn mathematics, and especially in algebraic geometry, the intersection number generalizes the intuitive notion of counting the number of times two curves intersect to higher dimensions, multiple (more than 2) curves, and accounting properly for tangency. One needs a definition of intersection number in order to state results like Bézout's theorem. The intersection number is obvious in certain cases, such as the intersection of the x- and y-axes in a plane, which should be one.
Courbe hyperelliptiquedroite|vignette|Une courbe hyperelliptique, d'équation En géométrie algébrique, une courbe hyperelliptique est un cas particulier de courbe algébrique de genre g > 1 donnée par une équation de la forme : où f(x) est un polynôme de degré n = 2g + 1 > 4 ou avec n = 2g + 2 > 4 racines distinctes et h(x) est un polynôme de degré strictement inférieur à g + 2 (si la caractéristique du corps commutatif n'est pas 2, on peut prendre h(x) = 0).
BiholomorphismIn the mathematical theory of functions of one or more complex variables, and also in complex algebraic geometry, a biholomorphism or biholomorphic function is a bijective holomorphic function whose inverse is also holomorphic. Formally, a biholomorphic function is a function defined on an open subset U of the -dimensional complex space Cn with values in Cn which is holomorphic and one-to-one, such that its is an open set in Cn and the inverse is also holomorphic. More generally, U and V can be complex manifolds.
MonodromieLa monodromie est l'étude du comportement de certains objets mathématiques « lorsqu'on tourne autour d'une singularité ». Un premier aspect de ce phénomène se rencontre dans le domaine des fonctions complexes admettant plusieurs déterminations dans le plan complexe épointé, comme le logarithme ou les puissances rationnelles : suivre continument une détermination d'une telle fonction le long d'un lacet autour de l'origine conduit après un tour à obtenir une autre détermination.
Cusp neighborhoodIn mathematics, a cusp neighborhood is defined as a set of points near a cusp singularity. The cusp neighborhood for a hyperbolic Riemann surface can be defined in terms of its Fuchsian model. Suppose that the Fuchsian group G contains a parabolic element g. For example, the element t ∈ SL(2,Z) where is a parabolic element. Note that all parabolic elements of SL(2,C) are conjugate to this element. That is, if g ∈ SL(2,Z) is parabolic, then for some h ∈ SL(2,Z).
Dessin d'enfant (mathématiques)En mathématiques, les dessins d'enfants, tels qu'ils ont été introduits par Alexandre Grothendieck dans son Esquisse d'un programme, sont des objets combinatoires permettant d'énumérer de manière simple et élégante les classes d'isomorphisme de revêtements étales de la droite projective privée de trois points. Le groupe de Galois absolu opérant de manière naturelle sur de tels revêtements, le but de la théorie des dessins d'enfants est de traduire cette action en termes combinatoires.
Regular map (graph theory)In mathematics, a regular map is a symmetric tessellation of a closed surface. More precisely, a regular map is a decomposition of a two-dimensional manifold (such as a sphere, torus, or real projective plane) into topological disks such that every flag (an incident vertex-edge-face triple) can be transformed into any other flag by a symmetry of the decomposition. Regular maps are, in a sense, topological generalizations of Platonic solids. The theory of maps and their classification is related to the theory of Riemann surfaces, hyperbolic geometry, and Galois theory.
Pair of pants (mathematics)In mathematics, a pair of pants is a surface which is homeomorphic to the three-holed sphere. The name comes from considering one of the removed disks as the waist and the two others as the cuffs of a pair of pants. Pairs of pants are used as building blocks for compact surfaces in various theories. Two important applications are to hyperbolic geometry, where decompositions of closed surfaces into pairs of pants are used to construct the Fenchel-Nielsen coordinates on Teichmüller space, and in topological quantum field theory where they are the simplest non-trivial cobordisms between 1-dimensional manifolds.
Théorème de Liouville (variable complexe)En analyse complexe, le théorème de Liouville est un résultat portant sur les fonctions entières (les fonctions holomorphes sur tout le plan complexe). Alors qu'il existe un grand nombre de fonctions infiniment dérivables et bornées sur la droite réelle, le théorème de Liouville affirme que toute fonction entière bornée est constante. Ce théorème est dû à Cauchy. Ce détournement est l'œuvre d'un élève de Liouville qui prit connaissance de ce théorème aux cours lus par ce dernier.