Jeong, Donghui, Komatsu, Eiichiro, Jain, Bhuvnesh
A convincing detection of primordial non-Gaussianity in the local form of the bispectrum, whose amplitude is given by the fNL parameter, offers a powerful test of inflation. In this paper we...
The Cosmic Near Infrared Background II: Fluctuations (2009)
Fernandez, Elizabeth R., Komatsu, Eiichiro, Iliev, Ilian T., Shapiro, Paul R.
The Near Infrared Background (NIRB) is one of a few methods that can be used to observe the redshifted light from early stars at a redshift of six and above. Fluctuations of the NIRB can provide...
Primordial non-Gaussianity, scale-dependent bias, and the bispectrum of galaxies (2009)
Jeong, Donghui, Komatsu, Eiichiro
We calculate the bispectrum, B_g(k_1,k_2,k_3), Fourier transform of the three-point function of density peaks (e.g., galaxies), using two different methods: the Matarrese-Lucchin-Bonometto formula...
Third-order Perturbation Theory With Non-linear Pressure (2009)
Shoji, Masatoshi, Komatsu, Eiichiro
We calculate the non-linear matter power spectrum using the 3rd-order perturbation theory without ignoring the pressure gradient term. We consider a semi-realistic system consisting of two matter...
Nitta, Daisuke, Komatsu, Eiichiro, Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
We calculate the bispectrum of the Cosmic Microwave Background (CMB) temperature anisotropies induced by the second-order fluctuations in the Boltzmann equation. In this paper, which is one of a...
Observing the Evolution of the Universe (2009)
Aguirre, James, Amblard, Alexandre, Ashoorioon, Amjad, Baccigalupi, Carlo, Balbi, Amedeo, Bartlett, James, ...
How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed...
Cooray, Asantha, Amblard, Alexandre, Beichman, Charles, Benford, Dominic, Bernstein, Rebecca, Bock, James, ...
(Brief Summary) What is the total radiative content of the Universe since the epoch of recombination? The extragalactic background light (EBL) spectrum captures the redshifted energy released from...
Gravitational Dark Matter Decay and the ATIC/PPB-BETS Excess (2009)
Takahashi, Fuminobu, Komatsu, Eiichiro
The hidden scalar field, which couples to the visible sector only through Planck-suppressed interactions, is a candidate for dark matter owing to its long lifetime. Decay of such a scalar field...
CMBPol Mission Concept Study: Probing Inflation with CMB Polarization (2008)
Baumann, Daniel, Jackson, Mark G, Adshead, Peter, Amblard, Alexandre, Ashoorioon, Amjad, Bartolo, Nicola, ...
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to...
CMBPol Mission Concept Study: Reionization Science with the Cosmic Microwave Background (2008)
Zaldarriaga, Matias, Colombo, Loris, Komatsu, Eiichiro, Lidz, Adam, Mortonson, Michael, Oh, S. Peng, ...
We summarize existing constraints on the epoch of reionization and discuss the observational probes that are sensitive to the process. We focus on the role large scale polarization can play....
CMBPol Mission Concept Study: Probing Inflation with CMB Polarization (2008)
Baumann, Daniel, Jackson, Mark G., Adshead, Peter, Amblard, Alexandre, Ashoorioon, Amjad, Bartolo, Nicola, ...
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to...
Shoji, Masatoshi, Jeong, Donghui, Komatsu, Eiichiro
We present a method for extracting the angular diameter distances, $D_A$, and the expansion rates, $H$, of the universe from the {\it two-dimensional} Baryon Acoustic Oscillations (BAO) in the galaxy...
Jeong, Donghui, Komatsu, Eiichiro
We calculate the non-linear galaxy power spectrum in real space, including non-linear distortion of the Baryon Acoustic Oscillations, using the standard 3rd-order perturbation theory (PT). The...
Harmonic Inpainting of the Cosmic Microwave Background Sky: Formulation and Error Estimate (2008)
Inoue, Kaiki Taro, Cabella, Paolo, Komatsu, Eiichiro
We develop a new interpolation scheme, based on harmonic inpainting, for reconstructing the cosmic microwave background temperature data within the Galaxy mask from the data outside the mask. We find...
Hill, Gary J., Gebhardt, Karl, Komatsu, Eiichiro, Drory, Niv, MacQueen, Phillip J., Adams, Josh, ...
Yadav, Amit P. S., Komatsu, Eiichiro, Wandelt, Benjamin D., Liguori, Michele, Hansen, Frode K., Matarrese, Sabino
In our recent paper (Yadav et al. 2007) we described a fast cubic (bispectrum) estimator of the amplitude of primordial non-Gaussianity of local type, f_{NL}, from a combined analysis of the Cosmic...
Gravitational inflaton decay and the hierarchy problem (2007)
Watanabe, Yuki, Komatsu, Eiichiro
We study implications of the large-N species solution to the hierarchy problem, proposed by G. Dvali, for reheating of the universe after inflation. Dvali's proposal contains additional N~10^{32}...
Nishizawa, Atsushi J., Komatsu, Eiichiro, Yoshida, Naoki, Takahashi, Ryuichi, Sugiyama, Naoshi
Non-linear evolution of density fluctuations yields secondary anisotropies in the cosmic microwave background (CMB), which are correlated with the same density fluctuations that can be measured by...
Temperature and Polarization CMB Maps from Primordial non-Gaussianities of the Local Type (2007)
Liguori, Michele, Yadav, Amit, Hansen, Frode K., Komatsu, Eiichiro, Matarrese, Sabino, Wandelt, Benjamin
The forthcoming Planck experiment will provide high sensitivity polarization measurements that will allow us to further tighten the f_NL bounds from the temperature data. Monte Carlo simulations of...
Fernandez, Elizabeth R., Komatsu, Eiichiro
Using a simple method to interpret the luminosity function of Ly-alpha emitters, we explore properties of Ly-alpha emitters from 5.7 < z < 8.8 with various assumptions about metallicity and stellar...
Sefusatti, Emiliano, Komatsu, Eiichiro
The greatest challenge in the interpretation of galaxy clustering data from any surveys is galaxy bias. Using a simple Fisher matrix analysis, we show that the bispectrum provides an excellent...
Angular power spectrum of gamma-ray sources for GLAST: blazars and clusters of galaxies (2007)
Ando, Shin'ichiro, Komatsu, Eiichiro, Narumoto, Takuro, Totani, Tomonori
Blazars, a beamed population of active galactic nuclei, radiate high-energy γ-rays, and thus are a good target for the Gamma Ray Large Area Space Telescope (GLAST). As the blazars trace the...
Ando, Shin'ichiro, Komatsu, Eiichiro, Narumoto, Takuro, Totani, Tomonori
The origin of the cosmic gamma-ray background (CGB) is a longstanding mystery in high-energy astrophysics. Possible candidates include ordinary astrophysical objects such as unresolved blazars, as...
Yadav, Amit P. S., Komatsu, Eiichiro, Wandelt, Benjamin D.
Measurements of primordial non-Gaussianity ($f_{NL}$) open a new window onto the physics of inflation. We describe a fast cubic (bispectrum) estimator of $f_{NL}$, using a combined analysis of...
Reheating of the universe after inflation with f(phi)R gravity (2006)
Watanabe, Yuki, Komatsu, Eiichiro
We show that reheating of the universe occurs spontaneously in a broad class of inflation models with f(phi)R gravity (phi is inflaton). The model does not require explicit couplings between phi and...
Ando, Shin'ichiro, Komatsu, Eiichiro, Narumoto, Takuro, Totani, Tomonori
The origin of the cosmic gamma-ray background (CGB) is a longstanding mystery in high-energy astrophysics. Possible candidates include ordinary astrophysical objects such as unresolved blazars, as...
Angular power spectrum of gamma-ray sources for GLAST: blazars and clusters of galaxies (2006)
Ando, Shin'ichiro, Komatsu, Eiichiro, Narumoto, Takuro, Totani, Tomonori
Blazars, a beamed population of active galactic nuclei, radiate high-energy gamma-rays, and thus are a good target for the Gamma Ray Large Area Space Telescope (GLAST). As the blazars trace the...
Hikage, Chiaki, Komatsu, Eiichiro, Matsubara, Takahiko
We derive analytical formulae for the Minkowski Functions of the cosmic microwave background (CMB) and large-scale structure (LSS) from primordial non-Gaussianity. These formulae enable us to...
Improved Calculation of the Primordial Gravitational Wave Spectrum in the Standard Model (2006)
Watanabe, Yuki, Komatsu, Eiichiro
We show that the energy density spectrum of the primordial gravitational waves has characteristic features due to the successive changes in the relativistic degrees of freedom during the radiation...
Jeong, Donghui, Komatsu, Eiichiro
We compare the non-linear matter power spectrum in real space calculated analytically from 3rd-order perturbation theory with N-body simulations at 1
Kogo, Noriyuki, Komatsu, Eiichiro
We calculate the cosmic microwave background (CMB) angular trispectrum, spherical harmonic transform of the four-point correlation function, from primordial non-Gaussianity in primordial curvature...
Cosmology with High-redshift Galaxy Survey: Neutrino Mass and Inflation (2005)
Takada, Masahiro, Komatsu, Eiichiro, Futamase, Toshifumi
(abridged) High-z galaxy redshift surveys open up exciting possibilities for precision determinations of neutrino masses and inflationary models. The high-z surveys are more useful for cosmology than...
Anisotropy of the cosmic gamma-ray background from dark matter annihilation (2005)
Ando, Shin'ichiro, Komatsu, Eiichiro
High-energy photons from dark matter annihilation contribute to the cosmic gamma-ray background (CGB). Since dark matter particles are weakly interacting, annihilation can happen only in high density...
The Cosmic Reionization History as Revealed by the CMB Doppler--21-cm Correlation (2005)
Alvarez, Marcelo A., Komatsu, Eiichiro, Doré, Olivier, Shapiro, Paul R.
We show that the epoch(s) of reionization when the ionization fraction of the universe is about half can be determined by correlating Cosmic Microwave Background (CMB) temperature maps with 21-cm...
The Cosmic Near Infrared Background: Remnant Light from Early Stars (2005)
Fernandez, Elizabeth, Komatsu, Eiichiro
The redshifted ultraviolet light from early stars at z ~ 10 contributes to the cosmic near infrared background. We present detailed calculations of its spectrum with various assumptions about...
Dark Matter Annihilation: the origin of cosmic gamma-ray background at 1-20 MeV (2005)
Ahn, Kyungjin, Komatsu, Eiichiro
The origin of the cosmic gamma-ray background at 1-20 MeV remains a mystery. We show that gamma-ray emission accompanying annihilation of 20 MeV dark matter particles explains most of the observed...
Ahn, Kyungjin, Komatsu, Eiichiro, Hoflich, Peter
The observed cosmic gamma-ray background at ~ MeV has often been attributed to Type Ia supernovae (SNIa). Since SNIa is close to a standard candle, one can calculate the gamma-ray intensity of SNIa...
Cosmological Lower Bound on Dark Matter Masses from the Soft Gamma-ray Background (2004)
Ahn, Kyungjin, Komatsu, Eiichiro
Motivated by a recent detection of 511 keV photons from the center of our Galaxy, we calculate the spectrum of the soft gamma-ray background of the redshifted 511 keV photons from cosmological halos....
Constraining the Topology of the Universe (2003)
Cornish, Neil J., Spergel, David N., Starkman, Glenn D., Komatsu, Eiichiro
The first year data from the Wilkinson Microwave Anisotropy Probe are used to place stringent constraints on the topology of the Universe. We search for pairs of circles on the sky with similar...
Measuring primordial non-Gaussianity in the cosmic microwave background (2003)
Komatsu, Eiichiro, Spergel, David N., Wandelt, Benjamin D.
We derive a fast way for measuring primordial non-Gaussianity in a nearly full-sky map of the cosmic microwave background. We find a cubic combination of sky maps combining bispectrum configurations...
The Pursuit of Non-Gaussian Fluctuations in the Cosmic Microwave Background (2002)
We present theoretical and observational studies of non-Gaussian fluctuations in CMB, by using the angular bispectrum and trispectrum. We predict the primary angular bispectrum from inflation, and...
The Sunyaev-Zel'dovich angular power spectrum as a probe of cosmological parameters (2002)
Komatsu, Eiichiro, Seljak, Uros
The angular power spectrum of the SZ effect, C_l, is a powerful probe of cosmology. It is easier to detect than individual clusters in the field, is insensitive to observational selection effects and...
Measurement of the cosmic microwave background bispectrum on the COBE DMR sky maps (2001)
Komatsu, Eiichiro, Wandelt, Benjamin D., Spergel, David N., Banday, Anthony J., Gorski, Krzysztof M.
We measure the angular bispectrum of the cosmic microwave background (CMB) radiation anisotropy from the COBE Differential Microwave Radiometer (DMR) four-year sky maps. The angular bispectrum is the...
Universal gas density and temperature profile (2001)
Komatsu, Eiichiro, Seljak, Uros
We present an analytic approach to predict gas density and temperature profiles in dark matter haloes. We assume that the gas density profile traces the dark matter density profile in outer parts of...
The pursuit of non-Gaussian fluctuations in the cosmic microwave background / (2001)
Thesis (doctoral)--Tohoku University.
CMB anisotropy from spatial correlations of clusters of galaxies (2000)
Komatsu, Eiichiro, Kitayama, Tetsu, Refregier, Alexandre, Spergel, David N., Pen, Ue-Li
The SZ effect from clusters of galaxies is a dominant source of secondary CMB anisotropy in the low-redshift universe. We present analytic predictions for the CMB power spectrum from massive halos...
Komatsu, Eiichiro, Spergel, David N.
Why is non-Gaussianity interesting? One of generic predictions from inflationary scenarios is that primordial fluctuations are exactly Gaussian in linear order; however, the non-linearity in the...
Komatsu, Eiichiro, Matsuo, Hiroshi, Kitayama, Tetsu, Hattori, Makoto, Kawabe, Ryohei, Kohno, Kotaro, ...
We report on mapping observations toward the region of the most luminous X-ray cluster RXJ1347-1145 (z=0.45) through the Sunyaev-Zel'dovich effect at 21GHz and 150GHz with the Nobeyama 45-m...
Acoustic Signatures in the Primary Microwave Background Bispectrum (2000)
Komatsu, Eiichiro, Spergel, David N.
If the primordial fluctuations are non-Gaussian, then this non-Gaussianity will be apparent in the cosmic microwave background (CMB) sky. With their sensitive all-sky observation, MAP and Planck...
Eiichiro Komatsu, Hiroshi Matsuo, Tetsu Kitayama, Makoto Hattori, Ryohei Kawabe, Kotaro Kohno, ...
We report on mapping observations toward the region of the most luminous X-ray cluster RX J1347-- 1145 (z = 0:45) through the Sunyaev--Zel'dovich effect at 21 GHz and 150 GHz with the Nobeyama...
Masahiro Takada, Eiichiro Komatsu, Toshifumi Futamase
We investigate the weak gravitational lensing effect that is due to the large-scale structure of the universe on two-point correlations of local maxima (hot spots) in the two-dimensional sky map of...
Takada, Masahiro, Komatsu, Eiichiro, Futamase, Toshifumi
We investigate the weak gravitational lensing effect due to the large-scale structure of the universe on two-point correlations of local maxima ({\em hotspots}) in the 2D sky map of the cosmic...
Sunyaev - Zel'dovich fluctuations from spatial correlations between clusters of galaxies (1999)
Komatsu, Eiichiro, Kitayama, Tetsu
We present angular power spectra of the cosmic microwave background radiation anisotropy due to fluctuations of the Sunyaev-Zel'dovich (SZ) effect through clusters of galaxies. A contribution from...
Cosmological Implications of Galaxy Clusters in X-Ray, Millimeter, and Submillimeter Bands (1999)
Suto, Yasushi, Kitayama, Tetsu, Komatsu, Eiichiro, Hattori, Makoto, Kawabe, Ryohei, Matsuo, Hiroshi, ...
Cosmological implications of clusters of galaxies are discussed with particular attention to their importance in probing the cosmological parameters. More specifically we compute the number counts of...
Komatsu, Eiichiro, Kitayama, Tetsu, Suto, Yasushi, Hattori, Makoto, Kawabe, Ryohei, Matsuo, Hiroshi, ...
We report on the detection of the Sunyaev -- Zel'dovich (SZ) signals toward the most luminous X-ray cluster RXJ1347-1145 at Nobeyama Radio Observatory (21 and 43 GHz) and at James Clerk Maxwell...
Komatsu, Eiichiro, Futamase, Toshifumi
We present complete constraints imposed from observations of the cosmic microwave background radiation (CMBR) on the chaotic inflationary scenario with a nonminimally coupled inflaton field proposed...
Sunyaev-Zeldovich Fluctuations From Spatial Correlations Between Clusters Of Galaxies (1999)
E. Komatsu, Eiichiro Komatsu, Tetsu Kitayama
We present angular power spectra of the cosmic microwave background radiation anisotropy due to fluctuations of the Sunyaev-Zeldovich (SZ) effect through clusters of galaxies. A contribution from the...
Komatsu, Eiichiro, Futamase, Toshifumi
We investigate a possibility to restrict the chaotic inflationary scenario with "large" nonminimally coupled inflaton("phi") field considered by Fakir and Unruh by means of the observed CMBR...