Title: Infrared interferometry of young stellar disks

Circumstellar disks around young stellar objects play a key role in the formation process of stars 
and provide the stage for planet formation. In spite of their importance for astrophysics, the 
structure of these disks and the accretion and outflow processes, through which they interact with  
their environment and the central star, are still strongly debated.

Since recently, infrared long-baseline interferometry allows us to spatially resolve the inner 
circumstellar environment, providing information which is highly complementary to the commonly 
applied spectral energy distribution (SED) modeling and line profile fitting techniques. In 
particular, the latest generation of infrared interferometric instruments combines high spatial 
resolution (typically a few milliarcseconds) with spectroscopic capabilities, allowing one to 
characterize the geometry of the continuum-emitting region over a wide spectral range or to 
spatially resolve the emitting region of spectral lines.

In this talk, I will discuss the substantially new constraints provided by this exciting 
observational technique and present some recent investigations in which we employed the Very Large 
Telescope Interferometer (VLTI) to study the geometry and physical conditions in the disks around 
Herbig Ae/Be stars and to resolve the accretion and outflow processes taking place in the 
inner-most few AU.