2018-08-15  11:55 hrs.

### Resonance Sequences and Focal Decompositions

#### Lev BirbrairUniversidad Federal de Ceará, Fortaleza, Brasil

Resonance sequences appeared Geometric Theory of Ordinary Differential equations as an invariant of the linear equations of the second order under the focal equivalence. It is defined as follows. Let A = {a_1,.... a_k} be a nite multiset of positive real numbers. Consider the sequence of all positive integers multiples of all a_i , and note the multiplicity of each term in this sequence. This sequence of multiplicities is called the resonance sequence generated by  {a_1.... a_k}.

We are going to show the relations with focal decompositions and show some properties of the resonances sequences.

#### Palapa Guillermo Torres -- Jueves 23 de junio de 2016, 16:00 horas

Unidad Cuernavaca del Instituto de Matemáticas UNAM