Below is the ascii version of the abstract for 14-37. The html version should be ready soon.

Alessio Fiscella, Raffaella Servadei and Enrico Valdinoci
Density properties for fractional Sobolev spaces
(475K, pdf)

ABSTRACT.  Aim of this paper is to give the details of 
the proof of some density properties of smooth and compactly supported 
functions in the fractional 
Sobolev spaces and suitable modifications of them, which have 
recently found application in variational problems. 
The arguments are rather technical, but, roughly 
speaking, they rely 
on a basic technique of convolution (which makes functions $C^\infty$), joined with a cut-off (which makes their support compact), 
with some care needed in order not to exceed the original support.