The objective of this dissertation is to construct structural representations of the solutions to Cauchy problems for weakly dissipative wave equations below scaling and to deduce Strichartz type estimate Lp − Lq, q ≥ ...

In this work we will present a new characterization of the Sobolev space W^{1,1}(\R^n) and also we give another proof of the characterization of the Sobolev space W^{1,p}(\R^n), 1<p<\infty, in terms of Poincaré inequalities. ...

This work aims at presenting some recent results on the theory of polar foliations, also know as singular riemannian foliations with sections, on nonpositively curved manifolds, as seen in T oben [24]. Polar actions are ...

In this work we will study the existence of nonnegative nontrivial weak solutions to singular elliptic equations involving the critical Caffarelli-Kohn- Nirenberg exponent and sign-changing functions. For this purpose, ...

This work intends to study the analytic wave front set and theC8wave front set ofupx,0q, assu-ming that the partial differential equationsut fpx,t,u,uxqpresents a solutionu upx,tqPCk

Given closed connected surfaces X and Y, integers n > 0 and d > 2, and for i = 1,..., n partitions (dy)j=i,...,mi of d. The 5-tuple (X, Y, n, d, (dij)) is called the branch datum of a candidate branched covering. Many works ...

In this work, we describe the Poincaré Compactification of polinomial vector fields and present two characterization of it.

Our goal in this work is to study a nonautonomous parabolic differential equation. We are going to show some results about existence of pullback attractors for this type of problem and for the equation without the delay.

This dissertation mainly follows the works of \cite{Gr2} and \cite{Gr5}. Considering $\mathbb{K}$ a field, algebraically closed with positive characteristic, we presented invariants of singularities in $\mathbb{K}[[\u ...