356 citations · 2.7k across the 47 of their papers we have counts for
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Anomalies on the Lattice, Homotopy of Quantum Cellular Automata, and a Spectrum of Invertible States
Alexander M. Czajka, Roman Geiko, Ryan Thorngren
We develop a rigorous topological theory of anomalies on the lattice, which are obstructions to gauging global symmetries and the existence of trivial symmetric states. We also con…
Charge pumps, pivot Hamiltonians and symmetry-protected topological phases
Nick. G. Jones, Ryan Thorngren, Ruben Verresen +1
Generalised charge pumps are topological obstructions to trivialising loops in the space of symmetric gapped Hamiltonians. We show that given mild conditions on such pumps, the ass…
Exact Chiral Symmetries of 3+1D Hamiltonian Lattice Fermions
Lei Gioia, Ryan Thorngren
We construct Hamiltonian models on a 3+1d cubic lattice for a single Weyl fermion and for a single Weyl doublet protected by exact (as opposed to emergent) chiral symmetries. In th…