Lengths of closed geodesics, counted with multiplicity, on a hyperbolic surface forms the length spectrum of the surface. There is a related notion of marked length spectrum. In this talk we shall recall these definitions, define the angle and the length-angle spectra and discuss some properties of the latter two spectra.
Links:
[1] http://www.mpim-bonn.mpg.de/de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/de/node/3444
[3] http://www.mpim-bonn.mpg.de/de/node/3050