Thermal dimension of quantum spacetime

Understand

Recent results suggest that a crucial crossroad for quantum gravity is the characterization of the effective dimension of spacetime at short distances, where quantum properties of spacetime become significant.

• This is relevant in particular for various scenarios of "dynamical dimensional reduction" which have been discussed in the literature.
• We are here concerned with the fact that the related research effort has been based mostly on analyses of the "spectral dimension", which involves an unphysical Euclideanization of spacetime and is highly sensitive to the off-shell properties of a theory.
• As here shown, different formulations of the same physical theory can have wildly different spectral dimension.