Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pilot-wave approaches to quantum field theory   The purpose of this paper is to present an overview of recent work on
pilot-wave approaches to quantum field theory. In such approaches, systems are
not only described by their wave function, as in standard quantum theory, but
also by some additional variables. In the non-relativistic pilot-wave theory of
de Broglie and Bohm those variables are particle positions. In the context of
quantum field theory, there are two natural choices, namely particle positions
and fields. The incorporation of those variables makes it possible to provide
an objective description of nature in which rather ambiguous notions such as
`measurement' and `observer' play no fundamental role. As such, the theory is
free of the conceptual difficulties, such as the measurement problem, that
plague standard quantum theory.

20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc