Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Cauchy problem in hybrid metric-Palatini f(X)-gravity   The well-formulation and the well-posedness of the Cauchy problem is
discussed for {\it hybrid metric-Palatini gravity}, a recently proposed
modified gravitational theory consisting of adding to the Einstein-Hilbert
Lagrangian an $f(R)$ term constructed {\it \`{a} la} Palatini. The theory can
be recast as a scalar-tensor one predicting the existence of a light long-range
scalar field that evades the local Solar System tests and is able to modify
galactic and cosmological dynamics, leading to the late-time cosmic
acceleration. In this work, adopting generalized harmonic coordinates, we show
that the initial value problem can always be {\it well-formulated} and,
furthermore, can be {\it well-posed} depending on the adopted matter sources.

26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph