Funding for this research was provided by:
MIUR - PRIN 2017 (2017JFFHSH)
Gruppo Nazionale per l’Analisi Matematica, la Probabilita e le loro Applicazioni (GNAMPAINdAM)
Gruppo Nazionale per il Calcolo Scienti co (GNCS-INdAM)
Article History
Received: 22 February 2021
Accepted: 26 May 2021
First Online: 9 June 2021
Declarations
:
: The authors declare that they have no conflict of interest.