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Updated: Nov 21, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
String Perturbation Theory on the Schwinger-Keldysh Time Contour
Petr Hořava1, Christopher J Mogni1
1Berkeley Center for Theoretical Physics and Department of Physics, University of California, Berkeley, California 94720-7300, USA and Lawrence Berkeley National Laboratory, Physics Division, Berkeley, California 94720-8162, USA.
Abstract:
We perform the large-N expansion in the Schwinger-Keldysh formulation of nonequilibrium quantum systems with matrix degrees of freedom and study universal features of the anticipated dual string theory. We find a rich refinement of the topological genus expansion: In the original formulation, the future time instant where the forward and backward branches of the Schwinger-Keldysh time contour meet is associated with its own world sheet genus expansion. After the Keldysh rotation, the world sheets decompose into a classical and quantum part.
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