Quantum quench in c = 1 matrix model and emergent spacetimes
Abstract
We consider quantum quench in largeN singlet sector quantum mechanics of a single hermitian matrix in the double scaling limit. The time dependent parameter is the selfcoupling of the matrix. We find exact classical solutions of the collective field theory of the eigenvalue density with abrupt and smooth quench profiles which asymptote to constant couplings at early and late times, and with the system initially in its ground state. With adiabatic initial conditions we find that adiabaticity is always broken regardless of the quench speed. In a class of quench profiles the saddle point solution for the collective field diverges at a finite time, and a further time evolution becomes ambiguous. However the underlying matrix model expressed in terms of fermions predict a smooth time evolution across this point. By studying fluctuations around the saddle point solution we interpret the emergent spacetimes. They generically have spacelike boundaries where the couplings of the fluctuations diverge and the semiclassical description fails. Only for very finely tuned quench profiles, the spacetime is normal.
 Publication:

Journal of High Energy Physics
 Pub Date:
 April 2020
 DOI:
 10.1007/JHEP04(2020)107
 arXiv:
 arXiv:1910.00123
 Bibcode:
 2020JHEP...04..107D
 Keywords:

 Matrix Models;
 Bosonic Strings;
 String Duality;
 High Energy Physics  Theory;
 Condensed Matter  Statistical Mechanics;
 General Relativity and Quantum Cosmology
 EPrint:
 44 pages, 15 figures