25628512
Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment.
Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.
118598825
A measurement of the cosmic microwave background B-mode polarization power spectrum at sub-degree scales with POLARBEAR
We report a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the POLARBEAR experiment in Chile. The faint B-mode polarization signature carries information about the universe's entire history of gravitational structure formation, and the cosmic inflation that may have occurred in the very early universe. Our measurement covers the angular multipole range 500 < ? < 2100 and is based on observations of an effective sky area of 25? with 3.'5 resolution at 150?GHz. On these angular scales, gravitational lensing of the CMB by intervening structure in the universe is expected to be the dominant source of B-mode polarization. Including both systematic and statistical uncertainties, the hypothesis of no B-mode polarization power from gravitational lensing is rejected at 97.2% confidence. The band powers are consistent with the standard cosmological model. Fitting a single lensing amplitude parameter ABB to the measured band powers, , where ABB = 1 is the fiducial WMAP-9 ?CDM value. In this expression, stat refers to the statistical uncertainty, sys to the systematic uncertainty associated with possible biases from the instrument and astrophysical foregrounds, and multi to the calibration uncertainties that have a multiplicative effect on the measured amplitude ABB .
118412548
Mission Design of LiteBIRD
LiteBIRD is a next-generation satellite mission to measure the polarization of the cosmic microwave background (CMB) radiation. On large angular scales the B-mode polarization of the CMB carries the imprint of primordial gravitational waves, and its precise measurement would provide a powerful probe of the epoch of inflation. The goal of LiteBIRD is to achieve a measurement of the characterizing tensor to scalar ratio $$r$$r to an uncertainty of $$\delta r=0.001$$δr=0.001. In order to achieve this goal we will employ a kilo-pixel superconducting detector array on a cryogenically cooled sub-Kelvin focal plane with an optical system at a temperature of 4 K. We are currently considering two detector array options; transition edge sensor (TES) bolometers and microwave kinetic inductance detectors. In this paper we give an overview of LiteBIRD and describe a TES-based polarimeter designed to achieve the target sensitivity of 2 $$\upmu $$μK arcmin over the frequency range 50–320 GHz.
123621972
N=(2,0) SUPERSTRING AS THE UNDERLYING THEORY OF SELF-DUAL YANG-MILLS THEORY
We study the condition of vanishing of beta-functions in the (2,0) heterotic σ-model coupled to background Yang-Mills field. The condition of vanishing β-functions restricts the background Yang-Mills fields to be self-dual in the critical real four-dimensional target space-time with the signature (2,2). This supports the suggestion of Ooguri and Vafa that the N=(2,0) heterotic superstring underlies the four-dimensional self-dual Yang-Mills theories and that the (2,0) heterotic superstring theory is, indeed, the fundamental underlying theory of all lower-dimensional (bosonic) soluble systems. It is shown that N=(2,0) heterotic σ-models in superspace couple precisely to the prepotential of the J-formulation of SDYM theory.
17552488
Comment on Shadow and Non-Shadow Extensions of the Standard Model
The models in the two papers hep-ph/0608068 and hep-ph/0701254 by Chang et al. with the so-called shadow gauge and scalar fields are nothing but convenient tailored versions of our model in hep-th/0403039. The same remarks applies to the work in hep-th/0612165 by Meissner and Nicolai.
16468601
Hodge duality and cosmological constant
We present a simple mechanism to eliminate cosmological constants both in supersymmetric and non-supersymmetric theories. This mechanism is based on the Hodge (Poincare) duality between a 0-form and D-form field strengths in D-dimensional spacetime. The new key ingredient is the introduction of an extra Chern–Simons term into the D-form field strength H dual to the 0-form field strength. Our formulation can also be made consistent with supersymmetry. Typical applications to four-dimensional N = 1 supergravity and to ten-dimensional type IIA supergravity are given. The success of our formulation for both supersymmetric and non-supersymmetric systems strongly indicates the validity of our mechanism even after supersymmetry breakings at the classical level. Our mechanism may well be applicable to quantized systems, at least for supersymmetric cases with fundamental D-brane actions available.
124627740
Supergravity as a special case of local nilpotent fermionic symmetry
We start with a four-dimensional (4D) system only with local nilpotent fermionic symmetry, and show that massive N = 1 supergravity is realized as a special case. Our field content in 4D is (eμ , ψμ, ωμ , χ), where ψμ I is a vector-spinor in the Majorana representation in four-dimenisons, while χ is a compensator Majorana spinor, and ωμ rs is the Lorentz connection in the firstorder formalism. Applying a similar method to 10D, we start with the field content (eμ , ψμ, ωμ , Aμνρ, Bμν , λ, φ, χ) with nilpotent fermionic symmetry, and show that the conventional massive type-IIA supergravity comes out as a special case of our system. These explicit results indicate that the most known massive supergravity theories are just special cases of more fundamental systems with nilpotent fermionic symmetry. Our nilpotent fermionic charge Nα satisfying {Nα, Nβ} = 0 resembles the Becchi-Rouet-Stora-Tyutin (BRST) charge QB in topological field theory with the ‘twisting of supersymmetry’. If we interpret our charge Nα as twisted supersymmetry, it becomes clear how our system evades the Haag-Lopuszanski-Sohnius theorem for the uniqueness of supergravity. PACS: 04.65.+e, 11.30.Pb, 11.15.-q, 12.60.Jv
50171016
Unimodular Supergravity
We present the locally supersymmetric formulation of unimodular gravity theory in D (1 ≤ D ≤ 11) dimensions, namely supergravity theory with the metric tensor whose determinant is constrained to be unity. In such a formulation, the usual fine-tuning of cosmological constant is no longer needed, but its value is understood as an initial condition. Moreover, the zero-ness of the cosmological constant is concluded as the most probable configuration, based on the effective vacuum functional. We also show that the closure of supersymmetry gauge algebra is consistent with the unimodular condition on the metric.