Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometry of cross ratio   Generalization of the cross ratio to polarizations of linear finite and
infinite-dimensional spaces (in particular to Sato Grassmannian) is given and
explored. This cross ratio appears to be a cocycle of the canonical
(tautalogical) bundle over the Grassmannian with coefficients in the sheaf of
its endomorphisms. Operator analog of the Schwarz differential is defined. Its
connections to linear Hamiltonian systems and Riccati equations are
established. These constructions aim to obtain applications to KP-hierarchy.

17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th