1. Sums of squares on real algebraic surfaces

   • Claus Scheiderer

   OriginalPaper 13 March 2006 Pages: 395 - 410

2. On Birkhoff Theorems for Lagrangian invariant tori with closed orbits

   • M. J. Dias Carneiro
   • Rafael O. Ruggiero

   OriginalPaper 15 February 2006 Pages: 411 - 432

3. Sur les espaces multisécants aux courbes algébriques

   • Patrick Le Barz

   OriginalPaper 06 February 2006 Pages: 433 - 452

4. Non-completeness of the Arakelov-induced metric on moduli space of curves

   • J. Jorgenson
   • J. Kramer

   OriginalPaper 07 February 2006 Pages: 453 - 463

5. Engel-like characterization of radicals in finite dimensional Lie algebras and finite groups

   • Tatiana Bandman
   • Mikhail Borovoi
   • Eugene Plotkin

   OriginalPaper 06 March 2006 Pages: 465 - 481

6. Seshadri constants on ruled surfaces: the rational and the elliptic cases

   • Luis Fuentes García

   OriginalPaper 06 March 2006 Pages: 483 - 505