https://doi.org/10.1140/epjc/s10052-019-7041-8
Regular Article - Theoretical Physics
Soliton fermionic number from the heat kernel expansion
1
Departamento de Matematica Aplicada, University of Salamanca, Salamanca, Spain
2
CMCC, Universidade Federal do ABC, Santo André, São Paulo, Brazil
3
Departamento de Fisica Fundamental, University of Salamanca, Salamanca, Spain
4
Physics Department, Tomsk State University, Tomsk, Russia
* e-mail: guilarte@usal.es
Received:
5
June
2019
Accepted:
10
June
2019
Published online:
20
June
2019
We consider different methods of calculating the (fractional) fermion number of solitons based on the heat kernel expansion. We derive a formula for the localized 
function that provides a more systematic version of the derivative expansion for spectral asymmetry and compute the fermion number in a multi flavor extension of the Goldstone–Wilczek model. We also propose an improved expansion of the heat kernel that allows the tackling of the convergence issues and permits an automated computation of the coefficients.
© The Author(s), 2019
