Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Normal Biconformal Spaces   A new 8-dimensional conformal gauging avoids the unphysical size change,
third order gravitational field equations, and auxiliary fields that prevent
taking the conformal group as a fundamental symmetry. We give the structure
equations, gauge transformations and intrinsic metric structure for the new
biconformal spaces. We prove that a torsion-free biconformal space with exact
Weyl form, closed dilational curvature and trace-free spacetime curvature
admits a sub-bundle of vanishing Weyl form homeomorphic to the Whitney sum
bundle of the tangent bundle and the bundle of orthonormal Lorentz frames over
4-dimensional spacetime. Conversely, any 4-dimensional spacetime extends
uniquely to such a normal biconformal space. The Einstein equation holds if and
only if the biconformal basis is orthonormal. Unconstrained antisymmetric trace
of the spacetime curvature provides a closed 2-form, independent of the Weyl
vector, consistently interpretable as the electromagnetic field. The trace of
the spacetime co-torsion decouples from gravitational sources and serves as
electromagnetic source.

21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph