Deviations from tidal torque theory: Evolution of the halo spin–filament alignment

The alignment between halo spins and the cosmic web is still poorly understood despite being a widely studied topic. Here, we study this within context of tidal torque theory (TTT) deviations from it. To end, analyze evolution shape spin direction proto-haloes, i.e. all volume elements associated to $z=0$ halo, with respect present-day filaments. We find that major axis proto-haloes undergoes change, strongly perpendicular filament spine in initial conditions, preferentially aligned at present time. In comparison, orientation shows only mild evolution: it starts slightly parallel spine, but subsequent evolution, up $z{\sim}1$, gradually changes its perpendicular. order these signals TTT framework, split haloes according their net growth median expectation, finding clear correlation spin--filament alignment. At time, whose grew most are ones while below expectation typically more aligned. dependence directions on already gets further modified by late-time, $z<2$, evolution. Also, mildly deviate predictions even high redshift, indicating need for extensions model.