21184459
Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background.
We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.
110431759
High-speed charge-to-time converter ASIC for the Super-Kamiokande detector
Abstract A new application-specific integrated circuit (ASIC), the high-speed charge-to-time converter (QTC) IWATSU CLC101, provides three channels, each consisting of preamplifier, discriminator, low-pass filter, and charge integration circuitry, optimized for the waveform of a photomultiplier tube (PMT). This ASIC detects PMT signals using individual built-in discriminators and drives output timing signals whose width represents the integrated charge of the PMT signal. Combined with external input circuits composed of passive elements, the QTC provides full analog signal processing for the detector's PMTs, ready for further processing by time-to-digital converters (TDCs). High-rate ( > 1 MHz ) signal processing is achieved by short-charge-conversion-time and baseline-restoration circuits. Wide-range charge measurements are enabled by offering three gain ranges while maintaining a short cycle time. QTC chip test results show good analog performance, with efficient detection for a single photoelectron signal, four orders of magnitude dynamic range ( 0.3 mV ∼ 3 V ; 0.2 ∼ 2500 pC ), 1% charge linearity, 0.2 pC charge resolution, and 0.1 ns timing resolution. Test results on ambient temperature dependence, channel isolation, and rate dependence also meet specifications.
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.
42639050
Development of New Front-End Electronics for Super-Kamiokande
Super-Kamiokande is a ring imaging water Cherenkov detector for astro-particle physics that consists of 50 kton pure water and about 13000 photomultiplier tubes (PMTs). We are planning to upgrade all the front-end electronics in next year. By high speed signal processing electronics, we will record all the hits of all the PMTs without any hardware filtering, aiming observations of much fainter signals of the supernova relic neutrinos, lower energy (~3 MeV) solar neutrinos, neutrino burst from nearby galactic supernova, and so on. The energy resolutions of multi-GeV atmospheric neutrino events will also be improved by the electronics. The new front-end electronics is based on a charge to time converter (QTC) and a multi-hit TDC. TCP/IP based readout channel is implemented to handle large amounts of data. We have developed a custom ASIC QTC and evaluated the characteristics of the chip and the prototypical board; high-speed (1 MHz cycle), high sensitivity for single photo-electron signal, good charge (0.1 pC RMS) and timing (0.3 ns RMS) responses, and wide charge dynamic range (2500 pC). In this paper, the design and the performance of the front-end board are discribed.
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 .
14708990
Interacting Vector-Spinor and Nilpotent Supersymmetry
We formulate an interacting theory of a vector-spinor field that gauges anticommuting spinor charges \{Q_\alpha{}^I, Q_\beta{}^J \} = 0 in arbitrary space-time dimensions. The field content of the system is (\psi_\mu{}^{\alpha I}, \chi^{\alpha I J}, A_\mu{}^I), where \psi_\mu{}^{\alpha I} is a vector-spinor in the adjoint representation of an arbitrary gauge group, and A_\mu{}^I is its gauge field, while \chi^{\alpha I J} is an extra spinor with antisymmetric adjoint indices I J. Amazingly, the consistency of the vector-spinor field equation is maintained, despite its non-trivial interactions.
620533
Generalized BF theory in superspace as the underlying theory of 11D supergravity
We construct a generalized BF theory in superspace that can embed eleven-dimensional supergravity theory. Our topological BF theory can accommodate all the necessary Bianchi identities for teleparallel superspace supergravity in eleven dimensions, as the simplest but nontrivial solutions to superfield equations for our superspace action. This indicates that our theory may have solutions other than eleven-dimensional supergravity accommodating generalized theories of eleven-dimensional supergravity. Therefore, our topological theory can be a good candidate for the low-energy limit of M-theory, as an underlying fundamental theory providing a 'missing link' between the eleven-dimensional supergravity and M-theory.
121022434
ENHANCED DUALITY SYMMETRIES FOR A PAIR OF DIRAC–BORN–INFELD ACTIONS
We consider a total action composed of two Dirac–Born–Infeld (DBI) actions: one for a vector field Aμ and another for an axial vector field Bμ. We impose a duality condition , where is the Hodge dual of Gμν, and g is a DBI interaction constant. Interestingly, there are two different global duality rotation symmetries in the presence of DBI interactions: (i) , , and (ii) δζAμ = - ζBμ, δζBμ = + ζAμ. Both of these symmetry are on-shell symmetries, including nonlinear higher-order terms. The remarkable aspect is that these symmetries are valid even in the presence of DBI interactions. The coupling of this system to N = 1 supergravity is also discussed.
119094505
Exact solutions for self-dual Yang-Mills and self-dual tensor multiplets on gravitational instanton background
Abstract We give exact solutions for recently developed N = 1 locally supersymmetric self-dual gauge theories in 2 + 2 dimensions. We give the exact solutions for an SL(2) self-dual Yang-Mills multiplet and what we call “self-dual tensor multiplet” on the gravitational instanton background by Eguchi and Hanson. We use a general method to get an SL(2) self-dual Yang-Mills solution from any known self-dual gravity solutions. Our result is the first example of exact solutions for the coupled system of these N = 1 locally supersymmetric self-dual multiplets in 2 + 2 dimensions, which is supposed to have strong significance for integrable models in lower dimensions upon appropriate dimensional reduction or truncation. We also inspect the consistency of our exact solutions as a background for the N = 2 superstring coupled to the Wess-Zumino-Witten term in σ-model formulation.
119082578
Self-dual supersymmetric Yang-Mills theory generates Witten's topological field theory
Abstract We show that the recently constructed N =4 supersymmetric self-dual Yang-Mills theory as the consistent background of the N =2 open superstring will generate Witten's topological field theory in two dimensions as a descendant theory after appropriate twisted dimensional reduction/truncations. We also show that this topological field theory further generates supersymmetric Korteweg de Vries equations, SL ( n )-Toda theory and W ∞ -gravity in the n →∞ limit. Considering also that this topological field theory is to generate other integrable and topological systems, our resutls give supporting evidence for the conjecture that the N =2 open superstring theory is the underlying “master theory” of integrable and topological systems, via the intermediate N =4 supersymmetric self-dual Yang-Mills theory as its consistent target space-time background.