TY - JOUR
T1 - Perturbation theory remixed
T2 - Improved nonlinearity modeling beyond standard perturbation theory
AU - Wang, Zhenyuan
AU - Jeong, Donghui
AU - Taruya, Atsushi
AU - Nishimichi, Takahiro
AU - Osato, Ken
N1 - Funding Information:
D. J. is supported by KIAS Individual Grant No. PG088301 at the Korea Institute for Advanced Study. This work was supported in part by MEXT/JSPS KAKENHI Grants No. JP19H00677 (T. N.), No. JP20H05861, No. JP21H01081 (A. T. and T. N.), No. JP21J00011, No. JP22K14036 (K. O.), and No. JP22K03634 (T. N.). We also acknowledge financial support from Japan Science and Technology Agency (JST) AIP Acceleration Research Grant No. JP20317829 (A. T. and T. N.). Numerical computations were carried out at the ROAR supercomputer at Penn State University, Yukawa Institute Computer Facility, and Cray XC50 at Center for Computational Astrophysics, National Astronomical Observatory of Japan.
Publisher Copyright:
© 2023 American Physical Society.
PY - 2023/5/15
Y1 - 2023/5/15
N2 - We present a novel nEPT (nth-order Eulerian perturbation theory) scheme to model the nonlinear density field by the summation up to nth-order density fields in perturbation theory. The obtained analytical power spectrum shows excellent agreement with the results from all 20 Dark-Quest suites of N-body simulations spreading over a broad range of cosmologies. The agreement is much better than the conventional two-loop standard perturbation theory and would reach out to kmax≃0.4 h/Mpc at z=3 for the best-fitting Planck cosmology, without any free parameters. We find that the nEPT results, particularly for n>4, depend sensitively on the grid size, but that can be removed by employing an effective field theory-type fitting function. The method can accelerate the forward modeling of the nonlinear cosmological density field, an indispensable probe of cosmic mysteries such as inflation, dark energy, and dark matter.
AB - We present a novel nEPT (nth-order Eulerian perturbation theory) scheme to model the nonlinear density field by the summation up to nth-order density fields in perturbation theory. The obtained analytical power spectrum shows excellent agreement with the results from all 20 Dark-Quest suites of N-body simulations spreading over a broad range of cosmologies. The agreement is much better than the conventional two-loop standard perturbation theory and would reach out to kmax≃0.4 h/Mpc at z=3 for the best-fitting Planck cosmology, without any free parameters. We find that the nEPT results, particularly for n>4, depend sensitively on the grid size, but that can be removed by employing an effective field theory-type fitting function. The method can accelerate the forward modeling of the nonlinear cosmological density field, an indispensable probe of cosmic mysteries such as inflation, dark energy, and dark matter.
UR - http://www.scopus.com/inward/record.url?scp=85161147564&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85161147564&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.107.103534
DO - 10.1103/PhysRevD.107.103534
M3 - Article
AN - SCOPUS:85161147564
SN - 2470-0010
VL - 107
JO - Physical Review D
JF - Physical Review D
IS - 10
M1 - 103534
ER -