Fixed points of Hammerstein-type equations on general cones
  We obtain new results on the existence and multiplicity of fixed points of Hammerstein equations in very general cones. In order to achieve this, we combine a new formulation of cones in terms of continuous functionals with fixed point index theory. Many examples and an application to boundary value problems are also included. 
Rub\'en Figueroa and F. Adri\'an F. Tojo
math.CA