Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resolving the Ostrogradsky Ghost Problem for a Class of Scalar-tensor
  Theories   We perform a Hamiltonian analysis and prove that a large class of
scalar-tensor theories whose Lagrangian is given by a generic function
$F\left(K_{ab},N,R_{ab},h^{ab},\nabla_a,t\right)$ is free from the Ostrogradsky
ghost, and thus these theories contain at most 3 degrees of freedom at
classical level.

36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat