6 papers
At the Corner of Space and Time
Barak Shoshany
We perform a rigorous piecewise-flat discretization of classical general relativity in the first-order formulation, in both 2+1 and 3+1 dimensions, carefully keeping track of curva…
Time Travel Paradoxes and Multiple Histories
Jacob Hauser, Barak Shoshany
If time travel is possible, it seems to inevitably lead to paradoxes. These include consistency paradoxes, such as the famous grandfather paradox, and bootstrap paradoxes, where so…
Spin Networks and Cosmic Strings in 3+1 Dimensions
Barak Shoshany
Spin networks, the quantum states of discrete geometry in loop quantum gravity, are directed graphs whose links are labeled by irreducible representations of SU(2), or spins. Cosmi…
Lectures on Faster-than-Light Travel and Time Travel
Barak Shoshany
These lecture notes were prepared for a 25-hour course for advanced undergraduate students participating in Perimeter Institute's Undergraduate Summer Program. The lectures cover s…
Dual 2+1D Loop Quantum Gravity on the Edge
Barak Shoshany
In a recent paper, we introduced a new discretization scheme for gravity in 2+1 dimensions. Starting from the continuum theory, this new scheme allowed us to rigorously obtain the…
2+1D Loop Quantum Gravity on the Edge
Laurent Freidel, Florian Girelli, Barak Shoshany
We develop a new perspective on the discretization of the phase space structure of gravity in 2+1 dimensions as a piecewise-flat geometry in 2 spatial dimensions. Starting from a s…