119 citations · 396 across the 27 of their papers we have counts for
28 papers
Dipolar power asymmetry in wide-angle correlations of galaxy density, velocity and ellipticity
Yusuke Mikura, Teppei Okumura, Ippei Obata +1
The large-scale structure of the universe has the potential to probe anomalies suggested by observations of the cosmic microwave background. In this work, we focus on a position-de…
Constraining Primordial Power Asymmetry from Galaxy Clustering and Peculiar Velocity Information
Keita Minato, Atsushi Taruya, Teppei Okumura +1
Primordial power asymmetry would probe departures from statistical isotropy, offering a clue to the physics of the primordial Universe. We investigate how such asymmetries can be t…
Joint Geometric and Dynamical Constraints on Cosmology from Anisotropies in Galaxy Intrinsic-Alignment Correlations
Teppei Okumura
We present the first joint cosmological analysis to extract both geometric and dynamical information from galaxy intrinsic alignments (IAs). Using BOSS spectroscopy cross-matched w…
Cosmological inference with halo clustering reconstructed from the redshift-space galaxy distribution
Ryuichiro Hada, Teppei Okumura
Accurate modeling of small-scale redshift-space clustering is crucial for full shape RSD analyses, where satellite galaxies contribute to 1-halo terms and Finger-of-God distortions…
Large-scale halo velocity correlations and the impact of finite simulation volumes
Yao-Tsung Chuang, Teppei Okumura, Takahiro Nishimichi
The velocity correlation functions directly measured from the peculiar velocity field of dark matter in numerical simulations are known to have an amplitude lower than that predict…
Clustering of emission line galaxies with IllustrisTNG -- II. cosmology challenge with anisotropic correlation functions and ELG-halo connections
Ken Osato, Teppei Okumura
Emission line galaxies (ELGs) are the primary tracers of the large-scale structures of the Universe in ongoing Stage-IV cosmological spectroscopic surveys, which aim to measure the…
Galaxy Spin Alignment with Tidal Fields in the SDSS-IV MaNGA Survey
Jun-Sung Moon, Teppei Okumura
The tidal torque theory (TTT) predicts that galaxy spins are correlated with the surrounding tidal field, reflecting how angular momentum is acquired during structure formation. We…
Cosmological constraints on nonphantom dynamical dark energy with DESI Data Release 2 Baryon Acoustic Oscillations: A 3+ lensing anomaly
Shouvik Roy Choudhury, Teppei Okumura, Keiichi Umetsu
We consider a 12-parameter cosmological model with non-phantom dynamical dark energy (NPDDE), where non-phantom implies that the equation of state (EoS) of dark energy (DE), $w(z)\…
Evidence for Intrinsic Galaxy Alignments in Ellipticity Autocorrelations out to from SDSS Galaxies with DESI Imaging
Teppei Okumura
Measuring the autocorrelation of galaxy shapes, known as the intrinsic-intrinsic (II) correlation, is important for both cosmology and understanding the formation of massive ellipt…
Imprints of gravitational-wave polarizations on projected tidal tensor in three dimensions
Yusuke Mikura, Teppei Okumura, Misao Sasaki
Gravitational waves (GWs) distort galaxy shapes through the tidal effect, offering a novel avenue to probe the nature of gravity. In this paper, we investigate how extra GW polariz…
SHAPE: cosmology with cluster halo intrinsic alignments from subhalo distributions
Shogo Ishikawa, Atsushi Taruya, Takahiro Nishimichi +2
Galaxy clusters trace the most massive dark matter haloes, whose shapes and orientations reflect the imprint of the cosmic large-scale tidal field. This paper introduces the Subhal…
Probing dipolar power asymmetry with galaxy clustering and intrinsic alignments
Keita Minato, Atsushi Taruya, Teppei Okumura +1
We investigate the prospects for probing large-scale statistical anisotropy through galaxy clustering and intrinsic alignments (IA) in Stage IV galaxy surveys. Specifically, we con…
A new constraint on galaxy-halo connections of [O II] emitters via HOD modelling with angular clustering and luminosity functions from the Subaru HSC survey
Shogo Ishikawa, Teppei Okumura, Masao Hayashi +1
Establishing a robust connection model between emission-line galaxies (ELGs) and their host dark haloes is of paramount importance in anticipation of upcoming redshift surveys. We…
Testing local position invariance with odd multipoles of galaxy clustering statistics
Takuya Inoue, Teppei Okumura, Shohei Saga +1
We investigate cosmological constraints on local position invariance (LPI), a key aspect of the Einstein equivalence principle (EEP), through asymmetric galaxy clustering. The LPI…
Improving cosmological constraints via galaxy intrinsic alignment in full-shape analysis
Junsup Shim, Teppei Okumura, Atsushi Taruya
The intrinsic alignment (IA) of galaxy shapes probes the underlying gravitational tidal field, thus offering cosmological information complementary to galaxy clustering. In this pa…
Squeezing Full-Shape Dynamical Dark Energy Constraints with Galaxy Alignments
Junsup Shim, Teppei Okumura, Atsushi Taruya
Recent deviations from the Cosmological Constant suggest that dark energy (DE) may be dynamical, based on baryon acoustic oscillations and full-shape galaxy clustering (…
Constraining cosmology with N-body simulations for future spectroscopic galaxy surveys at
Sy-Yun Pu, Teppei Okumura, Chian-Chou Chen +2
Determining the spatial curvature () independent of cosmic microwave background observations plays a key role in revealing the physics of the early universe. The Hubble tensio…
Updated Cosmological Constraints in Extended Parameter Space with Planck PR4, DESI Baryon Acoustic Oscillations, and Supernovae: Dynamical Dark Energy, Neutrino Masses, Lensing Anomaly, and the Hubble Tension
Shouvik Roy Choudhury, Teppei Okumura
We present updated constraints on cosmological parameters in a 12-parameter model, extending the standard six-parameter CDM by including dynamical dark energy (DE: , )…
First confirmation of anisotropic halo bias from statistically anisotropic matter distributions
Shogo Masaki, Maresuke Shiraishi, Takahiro Nishimichi +2
We confirm for the first time the existence of distinctive halo bias associated with the quadrupolar type of statistical anisotropy (SA) of the linear matter density field using co…
Improving redshift-space power spectra of halo intrinsic alignments from perturbation theory
Atsushi Taruya, Toshiki Kurita, Teppei Okumura
Intrinsic alignments (IAs) of galaxies/halos observed via galaxy imaging survey, combined with redshift information, offer a novel probe of cosmology as a tracer of the tidal force…
Intrinsic Alignments and Spin Correlations of [OII] Emitters at and from HSC Narrow-band Survey
Motonari Tonegawa, Teppei Okumura, Masao Hayashi
Galaxies are known to be aligned toward specific directions within the large-scale structure. Such alignment signals become important for controlling the systematics of weak lensin…
Information content in anisotropic cosmological fields: Impact of different multipole expansion scheme for galaxy density and ellipticity correlations
Takuya Inoue, Teppei Okumura, Shohei Saga +1
Multipole expansions have been often used for extracting cosmological information from anisotropic quantities in observation. However, which basis of the expansion is best suited t…
Probing vector chirality in the early Universe
Junsup Shim, Ue-Li Pen, Hao-Ran Yu +1
We explore the potential of using late-time galaxy spins to test the parity symmetry of primordial vector fossils. Using -body simulations, we analyze halo spins as a reliable p…
Extracting parity-violating gravitational waves from projected tidal force tensor in three dimensions
Teppei Okumura, Misao Sasaki
Gravitational waves (GWs) may be produced by various mechanisms in the early universe. In particular, if parity is violated, it may lead to the production of parity-violating GWs.…