13 papers
A Breathing Universe is Consistent
Samuel Blitz
We consider a toy FRW universe with the exotic topology . We show that for a specific choice of quantum field content, the semi-classical Friedman equations are con…
Unique Carrollian manifolds emerging from Einstein spacetimes
S. Blitz, D. McNutt, P. Nurowski
We explicitly determine all shear-free null hypersurfaces embedded in an Einstein spacetime, including vacuum asymptotically flat spacetimes. We characterize these hypersurfaces as…
Potential Carroll Structures and Special Carrollian Manifolds
Samuel Blitz, Gabriel Herczeg, David McNutt
It is well-known that unlike space-like and time-like hypersurfaces, null hypersurfaces in Lorentzian manifolds do not naturally inherit an affine connection from the spacetime in…
Einstein and Yang-Mills implies conformal Yang-Mills
Samuel Blitz, A. Rod Gover, JarosÅaw KopiÅski +1
There exist conformally invariant, higher-derivative, variational analogs of the Yang-Mills condition for connections on vector bundles over a conformal manifold of even dimension…
Conformal hypersurface invariants and Bach-type Boundary Problems
Samuel Blitz, A. Rod Gover
Using variational considerations, we establish that there exists a new symmetric trace-free tensor conformal invariant of hypersurfaces embeddings in even dimensional conformal man…
The Dirichlet-to-Neumann Map for Poincaré-Einstein Fillings
Samuel Blitz, A. Rod Gover, JarosÅaw KopiÅski +1
We study the non-linear Dirichlet-to-Neumann map for the Poincaré-Einstein filling problem. For even dimensional manifolds the range of this non-local map is described in terms of…