Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resurgence theory, ghost-instantons, and analytic continuation of path
  integrals   A general quantum mechanical or quantum field theoretical system in the path
integral formulation has both real and complex saddles (instantons and
ghost-instantons). Resurgent asymptotic analysis implies that both types of
saddles contribute to physical observables, even if the complex saddles are not
on the integration path i.e., the associated Stokes multipliers are zero. We
show explicitly that instanton-anti-instanton and ghost--anti-ghost saddles
both affect the expansion around the perturbative vacuum. We study a self-dual
model in which the analytic continuation of the partition function to negative
values of coupling constant gives a pathological exponential growth, but a
homotopically independent combination of integration cycles (Lefschetz
thimbles) results in a sensible theory. These two choices of the integration
cycles are tied with a quantum phase transition. The general set of ideas in
our construction may provide new insights into non-perturbative QFT, string
theory, quantum gravity, and the theory of quantum phase transitions.

20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int