“…The calculation of the differential operator spectrum is a mathematical problem with important applications in theoretical physics; it defines the relation between matter fields and quantum corrections to the geometry (for general introduction, see [2,3]). Among various papers that investigate these physical applications, we can cite [4,5,6,7,8,9,10,11,12]. One can mention that the papers [4,5,6,7,8,9,10] consider torsion, which gives the general coupling between geometry and fermions (see also [3] and [13]).…”