ALGEBRAIC GEOMETRY 2 |
Undergraduate and Graduate studies in Mathematics |
Roma
Tre University |
A.Y. 2018/2019 |
Sheaf theory and its use in schemes |
Presheaves and
sheaves, sheaf associated to a presheaf, relation
between injectivity and bijectivity on the stalks and analogous properties on the sections. The category of ringed spaces. Schemes. Examples. Fiber products. Algebraic sheaves on a scheme. Quasi-coherent and coherent sheaves. |
Sheaf cohomology |
Homological
algebra in the category of
modules over a ring. Flasque
sheaves. Cohomology of sheaves using the canonical resolution with flasque sheaves. |
Cohomology of quasi-coherent and coherent sheaves on a scheme | Cech cohomology and ordinary cohomology.
Cohomology of quasi-coherent sheaves on an affine scheme. The cohomology of the sheaves O(n) on the projective space. Coherent sheaves on projective space. Euler-Poincaré characteristic. |
Invertible sheaves and linear systems | Glueing of sheaves. Invertible sheaves and
their description. The Picard group. Morphisms in a projective space. Linear systems. Base points. Ample and very ample linear systems and sheaves. Criteria for ampleness. |