Facial structure of the cone of nonnegative ternary quartics
  In this work we will discuss the facial structure of the cone of nonnegative ternary quartics with real coefficients. We will establish an equivalence relation on the set of all faces, which preserves certain properties like dimension or the number of common zeros. Moreover we will give a complete list of equivalence classes and we will discuss their dimension and inclusions between them. Eventually we will be able to present a complete lattice of all faces of this particular cone. 
Aaron Kunert
math.AG