Comment on “Einstein–Cartan fermion condensates trapped in double walls induce axial torsion coupling bounds [Eur. Phys. J. C (2026) 86: 785]”

Abstract

We point out several algebraic and dimensional inconsistencies in the derivation of the teleparallel double-wall dynamics and of the axial torsion coupling bound published in this Journal [Eur. Phys. J. C (2026) 86: 785]. Recomputing the torsion two-forms from the tetrads with vanishing spin connection, we obtain expressions that differ from those used in the paper. Consequently, the equations for the wall separation function do not lead to the reported solution, and the approximation \(h^2\ll z^2\) does not restore the polynomial form adopted there. We also show that the proposed wave equation for the wall separation and the corresponding gravitational-wave interpretation require rederivation. In the fermionic sector, the zero-mode solutions and the scalar Dirac bilinear must be distinguished from the positive density \(\varPsi ^\dagger \varPsi \). With the corrected solutions, the effective coefficient \(A=eB+g_T S\) determines a localization length \(\ell _{\textrm{loc}}\sim |A|^{-1/2}\), so that estimating \(g_T\) requires specifying an additional physical scale rather than imposing \(A=0\). Hence the claimed constant condensate and the bound \(g_T\sim 10^{-4}\) are not established by the calculations presented.