Toshiya Namikawa ( Kyoto University )

1. P-27 Lensing reconstruction from CMB polarization map with bias-hardened approach Brief Summary Toshiya Namikawa( Kyoto University) We explore significance of masking effect in the mean-field bias. We show that, for some cases, the mask mean-field has non-negligible contributions from 2nd order of mask-field. If the mask mean-field is non-negligible in the lensing signals, we may thus improve the bias-hardened estimator for mitigating 2nd order of mask-field. Current Collaborators Duncan Hanson ( McGill University ),RyuichiTakahashi( Hirosaki University ) Constraints on cosmic string parameters with ACT curl mode measurement 1. Introduction 2) From curl mode (e.g., Cooray+’05; TN+’12; Book+’12; Yamauchi+’12; Yamauchi+’13 ) • Cosmology in the last decade An example of cosmological probes: CMB • The curl mode measured from ACT data (http://lambda.gsfc.nasa.gov/) is noisy, and the constraints on, e.g., cosmic string parameters are weak compared to those from temperature power spectrum. The measurement of curl mode, however, would be a new probe of cosmic strings, and have complementarity to constraints from temperature power spectrum • Cosmological observations in the last decade have successfully led to the establishment of afundamental framework in cosmology. COBE Planck Flat Lambda CDM model Planck WMAP WMAP Planck Results XVIII (2013) Primary CMB + CMB lensing Primary CMB alone 3) Other motivations to measure CMB lensing taken from NASA and ESA web sites • Lensing mixes E and B-mode polarizations. The lensing B-mode may be required to remove for detecting primordial GWs with small tensor-to-scalar ratio ( 0.01). • In particular, the observations of CMB, (or combining type-Iasupernovae, and large scale structure) revealed that the energy composition of the universe is well described by a flat Lambda Cold Dark Matter (CDM) model. (TN,Yamauchi&Taruyain prep. ) taken from ESA web site (e.g., Knox+’02, Kesden+’02, Smith+’09) • Cosmology in the next decades • Taking seriously account of our current understanding and lack of our knowledge of the universe, cosmology in the coming decade should focus on more advanced and fundamental issues! e.g., physical origin of accelerating expansion and dark matter measuring mass of neutrinos for model beyond standard model in particle physics pure E E/B-mixed physical description of the early stage of the universe 2. Weak gravitational lensing of CMB (CMB Lensing) 3. Lensing reconstruction from CMB maps • Lensing effect on CMB (Reviews :Lewis&Challinor’06; Hanson+’10) • How to measure lensing effect • Lensed B-mode power spectrum • The CMB photons emitted from the last scattering surface move through the gravitational fields generated by the large scale structure, and their path is deflected. As a result, the spatial pattern of observed anisotropies are distorted and statistical quantities, e.g., the CMB angular power spectrum, bispectrum, trispectrum, is modified. • Lensing reconstruction (trispectrum induced by lensing) • Minkowskifunctionals (partially include higher order statistics than trispectrum) (e.g., Schmalzing+’00; TN&Takeuchi in prep.) Deflection angle • Lensing reconstruction (Review: Hanson+’10) • Lensing induces mode coupling in the primary anisotropies and mixing E and B modes observer Last scattering surface Distance Lensing potential • Lensed CMB fluctuations Gravitational potential • Lensing potentials would be estimated from mode coupling • A conventional (and numerically convenient) estimator is (e.g., Hu&Okamoto’02) Mean-field bias: induced by non-lensing effect (mask, inhomogeneous noise, beam asymmetry, …) • General description of deflection angle (e.g., Dodelson+’03; TN+’12; Yamauchi+’12; Yamauchi+’13) • In the presence of vector and/or tensor metric perturbations, the deflection angle has additional term, which is usually called curl mode. The application of curl mode to cosmology is to probe vector and tensor sources, e.g., gravitational waves, cosmic strings, magnetic fields. Even if these sources are negligible, the measurement of curl mode is still important for checking systematics. includes lensed Cl’s gradient scalar • Mean-field bias linear density fluctuations • Mean-field bias is usually estimated with Monte Carlo, but the underlying fluctuations should be perfectly known. Thus, alternative method would be required to cross-check each other. curl vector, tensor magnetic fields cosmic strings gravitational waves rotating vector on 2D plane from ESA from NASA 4. Results • Cosmological implications from CMB lensing Effects of massive neutrinos • Power spectrum of mean-filed bias 1) From gradient mode (e.g., Hu’01; Lesgourgues&Pastor’06; TN+’10) • We show the mean-field bias from survey boundary effect. We also construct the mask estimator in the case of polarization with the similar analogy of temperature (TN, Hanson & Takahashi’13), and show whether mask estimator correctly estimates the mask field. Angular power spectrum • Dark energy • Properties of dark energy affects on the expansion rate, , and thus, on growth of matter density fluctuations. curl mask gradient • Massive neutrinos • At small scales, the density fluctuations of neutrinos do not grow because of their velocity dispersion, and neutrinos do not contribute to gravitational clustering. • Total mass of neutrinos also affects on • Comparing green (mean-field bias) with black symbols (expected from 1st order of mask field), the 2nd order of mask field is non-negligible, and we may need to improve the bias-hardened estimator for subtraction of mask mean-field. On the other hand, curl mode is free from mask-mean field. affects on lensing potential through and gravitational potential Large scale CMB international workshop @ OIST, June 10-14, 2013