12 citations · 31 across the 9 of their papers we have counts for
5 papers · 1 filter
The enigmatic gravitational partition function
Batoul Banihashemi, Ted Jacobson
The saddle point approximation to formal quantum gravitational partition functions has yielded plausible computations of horizon entropy in various settings, but it stands on shaky…
Feynman 1947 letter on path integral for the Dirac equation
Ted Jacobson
In 1947, four months before the famous Shelter Island conference, Richard Feynman wrote a lengthy letter to his former MIT classmate Theodore Welton, reporting on his efforts to de…
Guiding-centre Lagrangian and quasi-symmetry
Ted Jacobson
A charged particle in a suitably strong magnetic field spirals along the field lines while slowly drifting transversely. This note provides a brief derivation of an effective Lagra…
On the lapse contour in the gravitational path integral
Batoul Banihashemi, Ted Jacobson
The gravitational path integral is usually implemented with a covariant action by analogy with other gauge field theories, but the gravitational case is different in important ways…
De Sitter horizon entropy from a simplicial Lorentzian path integral
Bianca Dittrich, Ted Jacobson, José Padua-Argüelles
The dimension of the Hilbert space of a quantum gravitational system can be written formally as a path integral partition function over Lorentzian metrics. We implement this in a 2…