  Tensor models are used nowadays for implementing a fundamental theory of
quantum gravity. We define here a polynomial $\mathcal T$ encoding the
supplementary topological information. This polynomial is a natural
generalization of the Bollob\'as-Riordan polynomial (used to characterize
matrix graphs) and is different of the Gur\uau polynomial, (R. Gur\uau,
"Topological Graph Polynomials in Colored Group Field Theory", Annales Henri
Poincare {\bf 11}, 565-584 (2010)) defined for a particular class of tensor
graphs, the colorable ones. The polynomial $\mathcal T$ is defined for both
colorable and non-colorable graphs and it is proved to satisfy the
contraction/deletion relation. A non-trivial example of a non-colorable graphs
is analyzed.

Combinatorics;General Relativity and Quantum Cosmology