Combinatorics

Discrete mathematics

Physics

Graph

Finite element method

Quadrilateral

Pure mathematics

Mathematics

Binomial coefficient

Indecomposable module

Quiver

Newton polygon

Rational number

Farey sequence

Thermodynamics

Forum of Mathematics Sigma

We introduce a notion of $q$-deformed rational numbers and $q$-deformed continued fractions. A $q$-deformed rational is encoded by a triangulation of a polygon and can be computed recursively. The recursive formula is analogous to the $q$-deformed Pascal identitiy for the Gaussian binomial coefficients, but the Pascal triangle is replaced by the Farey graph. The coefficients of the polynomials defining the $q$-rational count quiver subrepresentations of the maximal indecomposable representation of the graph dual to the triangulation. Several other properties, such as total positivity properties, $q$-deformation of the Farey graph, matrix presentations and $q$-continuants are given, as well as a relation to the Jones polynomial of rational knots.

-DEFORMED RATIONALS AND -CONTINUED FRACTIONS