%0 Thesis %D 2015 %T Multidimensional Poisson Vertex Algebras and Poisson cohomology of Hamiltonian operators of hydrodynamic type %A Matteo Casati %K Poisson Vertex Algebras, Poisson brackets, Hamiltonian operators, Integrable Systems %X The Poisson brackets of hydrodynamic type, also called Dubrovin-Novikov brackets, constitute the Hamiltonian structure of a broad class of evolutionary PDEs, that are ubiquitous in the theory of Integrable Systems, ranging from Hopf equation to the principal hierarchy of a Frobenius manifold. They can be regarded as an analogue of the classical Poisson brackets, defined on an infinite dimensional space of maps Σ → M between two manifolds. Our main problem is the study of Poisson-Lichnerowicz cohomology of such space when dim Σ > 1. We introduce the notion of multidimensional Poisson Vertex Algebras, generalizing and adapting the theory by A. Barakat, A. De Sole, and V. Kac [Poisson Vertex Algebras in the theory of Hamiltonian equations, 2009]; within this framework we explicitly compute the first nontrivial cohomology groups for an arbitrary Poisson bracket of hydrodynamic type, in the case dim Σ = dim M = 2. For the case of the so-called scalar brackets, namely the ones for which dim M = 1, we give a complete description on their Poisson–Lichnerowicz cohomology. From this computations it follows, already in the particular case dim Σ = 2, that the cohomology is infinite dimensional. %I SISSA %G en %1 34902 %2 Mathematics %4 1 %# MAT/07 %$ Submitted by Matteo Casati (mcasati@sissa.it) on 2015-10-22T07:27:52Z No. of bitstreams: 1 PhDThesis_Casati.pdf: 1027291 bytes, checksum: 49f551db40603ca035f2515ccb6ec7a2 (MD5)