Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Toward a QFT treatment of nonexponential decay   We study the properties of the survival probability of an unstable quantum
state described by a Lee Hamiltonian. This theoretical approach resembles
closely Quantum Field Theory (QFT): one can introduce in a rather simple
framework the concept of propagator and Feynman rules, Within this context, we
re-derive (in a detailed and didactical way) the well-known result according to
which the amplitude of the survival probability is the Fourier transform of the
energy distribution (or spectral function) of the unstable state (in turn, the
energy distribution is proportional to the imaginary part of the propagator of
the unstable state). Typically, the survival probability amplitude is the
starting point of many studies of non-exponential decays. This work represents
a further step toward the evaluation of the survival probability amplitude in
genuine relativistic QFT. However, although many similarities exist, QFT
presents some differences w.r.t. the Lee Hamiltonian which should be studied in
the future.

28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an