We study the generalized Hamiltonian dynamics of an implicit Hamiltonian system considered as a Lagrangian variety in the symplectic tangent bundle. Singularities of such systems where already considered by J. Basto-Goncalves and A. Davydov. We investigate the global properties of compact,...

Nekrasov has shown how the low-energy behaviour of certain super-symmetric quantum field theories can be derived from calculating equivariant volumes of moduli-spaces of instantons. From a mathematical point of view this work generates a number of remarkable conjectures in algebraic geometry. ...

A model of relationship between the production and ecological carrying capacity of shellfish cultured species (mussels, oysters, clams, etc.) and the spatial distribution of shellfish density within a licensed
...

Consider a smooth 2-dimensional surface $S$ with coordinates $(t,x)$ and pseudo-Riemann metric, i.e., the quadratic form
...

Complex algebraic surfaces of general type with $p_g=q=1$ are still not completely understood. Until recently only a few examples were known. In this talk I will use the Computational Algebra System Magma to construct such a surface with $K^2=6,$ as a double cover of a Kummer surface (quartic...

Every complex projective algebraic surface S satises the inequality
...

Let X and X' be a smooth projective curves over the complex numbers, the classical Torelli theorem says that the Jacobian J(X) together with the polarization given by the theta divisor determines the
...

Representations of surface groups into SL(3,C) are parameterized by conjugacy classes. When classes whose closures intersect are identified, the space of representations forms an algebraic quotient known as a character variety. This moduli space has a natural Poisson geometry which depends on...

É um resultado clássico que as transformações canónicas (simplécticas) preservam o volume, mas só a partir do trabalho de J. Moser (1965) e M. Gromov (1985) se começou a compreender bem que associados às
...