## View abstract

### Session S12 - Delay and functional differential equations and applications

Wednesday, July 21, 17:45 ~ 18:20 UTC-3

## Periodic positive solutions of superlinear delay equations via topological degree

### Pierluigi Benevieri

#### Universidade de São Paulo, Brasil   -   This email address is being protected from spambots. You need JavaScript enabled to view it. document.getElementById('cloak7e65ff35b051d913d43d7d5f9c28eddc').innerHTML = ''; var prefix = '&#109;a' + 'i&#108;' + '&#116;o'; var path = 'hr' + 'ef' + '='; var addy7e65ff35b051d913d43d7d5f9c28eddc = 'pl&#117;&#105;g&#105;' + '&#64;'; addy7e65ff35b051d913d43d7d5f9c28eddc = addy7e65ff35b051d913d43d7d5f9c28eddc + '&#105;m&#101;' + '&#46;' + '&#117;sp' + '&#46;' + 'br'; var addy_text7e65ff35b051d913d43d7d5f9c28eddc = 'pl&#117;&#105;g&#105;' + '&#64;' + '&#105;m&#101;' + '&#46;' + '&#117;sp' + '&#46;' + 'br';document.getElementById('cloak7e65ff35b051d913d43d7d5f9c28eddc').innerHTML += '<a ' + path + '\'' + prefix + ':' + addy7e65ff35b051d913d43d7d5f9c28eddc + '\'>'+addy_text7e65ff35b051d913d43d7d5f9c28eddc+'<\/a>';

In recent years, some papers by G. Feltrin and F. Zanolin have been devoted to the study of existence and multiplicity of periodic solutions to nonlinear differential equations of the form $u''=f(t,u,u'),$ with periodic or Newmann boundary conditions and suitable assumptions on $f$. In a recent joint work with P. Amster and J. Haddad, that I present in the talk, existence and multiplicity of periodic solutions is proven for a class of delay equations of the type $u''(t)=f(t,u(t),u(t-\tau),u'(t)).$ The approach is, as in the work of Feltrin and Zanolin, topological and based of the coincidence degree introduced by J. Mawhin.