Horizon charges and quasilocal first law in Lovelock gravity

In gravity, mass and angular momentum of a given spacetime
arises as boundary charges corresponding to the residual diffeomorphisms.
Black hole horizons may also be considered  as inner boundaries of the
spacetime and therefore, such surfaces are also expected to admit
Hamiltonian charges.  We construct the charges associated with the
residual local Lorentz transformations of a black hole horizon in the
Lovelock class of theories of gravity and show the Hamiltonian charge
corresponding to the residual local Lorentz boost is the Wald entropy. 
This presents an alternative perspective to black hole entropy. Further we
also show, using the covariant phase space techniques, how explicit
expressions for mass and angular momentum in terms of the Newman Penrose
coefficients may be obtained for black holes in any theory of gravity.