Centers of inscribed circles in triangular orbits of an elliptic   billiard
  The locus of centers of inscribed circles in triangles, the 3-periodic orbits of an elliptic billiard, is also an ellipse. In this work we obtain the canonical equation of this ellipse, complementing the previous results obtained by O. Romaskevich. 
Ronaldo A. Garcia
math.MG math.DS