Perturbation theory remixed: Improved nonlinearity modeling beyond standard perturbation theory

We present a novel $n$EPT ($n$th-order Eulerian Perturbation Theory) scheme to model the nonlinear density field by summation up $n$th-order fields in perturbation theory. The obtained analytical power spectrum shows excellent agreement with results from all 20 Dark-Quest suites of $N$-body simulations spreading over broad range cosmologies. is much better than conventional two-loop Standard Theory and would reach out $k_{\rm max}\simeq 0.4~h/{\rm Mpc}$ at $z=3$ for best-fitting Planck cosmology, without any free parameters. method can accelerate forward modeling non-linear cosmological field, an indispensable probe cosmic mysteries such as inflation, dark energy, matter.