Modeling iterative reconstruction and displacement field in the large scale structure

The next generation of galaxy surveys like the Dark Energy Spectroscopic Instrument (DESI) and Euclid will provide datasets orders magnitude larger than anything available to date. Our ability model nonlinear effects in late time matter perturbations be a key unlock full potential these datasets, area initial condition reconstruction is attracting growing attention. Iterative developed Ref. [1] technique designed reconstruct displacement field from observed distribution. linear density are highly correlated. Therefore, reconstructing enables us extract primordial cosmological information better at level two-point statistics. This paper test what extent iterative can recover true construct perturbation theory for postreconstructed field. We process with Lagrangian theory~(LPT) up third order dark real space compare it $N$-body simulations. find that simulated does not converge field, discrepancy mainly appears shift term, i.e., term correlated directly On contrary, our 3LPT predicts should discuss sources discrepancy, including numerical noise/artifacts on small scales, present an ad hoc phenomenological improves agreement.