A. C. Weber

Bio: A. C. Weber is an academic researcher from Jet Propulsion Laboratory. The author has contributed to research in topics: Cosmic microwave background & Neutrino. The author has an hindex of 17, co-authored 53 publications receiving 1678 citations.

Constraints on Primordial Gravitational Waves Using Planck, WMAP, and New BICEP2/Keck Observations through the 2015 Season.

Abstract: We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including the 2015 observing season. This includes the first Keck Array observations at 220 GHz and additional observations at 95 and 150 GHz. The Q and U maps reach depths of 5.2, 2.9, and 26 μKCMB arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈400 square degrees. The 220 GHz maps achieve a signal to noise on polarized dust emission approximately equal to that of Planck at 353 GHz. We take auto and cross spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz. We evaluate the joint likelihood of the spectra versus a multicomponent model of lensed-ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and we impose priors on some of these using external information from Planck and WMAP derived from larger regions of sky. The model is shown to be an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r0.05<0.07 at 95% confidence, which tightens to r0.05<0.06 in conjunction with Planck temperature measurements and other data. The lensing signal is detected at 8.8σ significance. Running a maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.020. These are the strongest constraints to date on primordial gravitational waves.

Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season.

Abstract: We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to and including the 2018 observing season. We add additional Keck Array observations at 220 GHz and BICEP3 observations at 95 GHz to the previous 95 / 150 / 220 GHz dataset. The Q / U maps now reach depths of 2.8, 2.8, and 8.8 μ K CMB arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈ 600 square degrees at 95 GHz and ≈ 400 square degrees at 150 and 220 GHz. The 220 GHz maps now achieve a signal-to-noise ratio on polarized dust emission exceeding that of Planck at 353 GHz. We take auto- and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz and evaluate the joint likelihood of the spectra versus a multicomponent model of lensed Λ CDM + r + dust + synchrotron + noise . The foreground model has seven parameters, and no longer requires a prior on the frequency spectral index of the dust emission taken from measurements on other regions of the sky. This model is an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r 0.05 0.036 at 95% confidence. Running maximum likelihood search on simulations we obtain unbiased results and find that σ ( r ) = 0.009 . These are the strongest constraints to date on primordial gravitational waves.

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) : 2: The Physics Program for DUNE at LBNF

Abstract: The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described.

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE)

Abstract: This document presents the Conceptual Design Report (CDR) put forward by an international neutrino community to pursue the Deep Underground Neutrino Experiment at the Long-Baseline Neutrino Facility (LBNF/DUNE), a groundbreaking science experiment for long-baseline neutrino oscillation studies and for neutrino astrophysics and nucleon decay searches. The DUNE far detector will be a very large modular liquid argon time-projection chamber (LArTPC) located deep underground, coupled to the LBNF multi-megawatt wide-band neutrino beam. DUNE will also have a high-resolution and high-precision near detector.

Expression of Interest for a very long baseline neutrino oscillation experiment (LBNO)

Abstract: This Expression of Interest (EoI) describes the motivation for and the feasibility studies of a long baseline neutrino oscillation experiment (LBNO) with a new conventional neutrino beamline facility (CN2PY). The beam will be aimed at a next generation deep-underground neutrino observatory comprising a double phase liquid argon (LAr) detector and a magnetized iron calorimeter, located at the Pyhasalmi (Finland) mine at a distance of 2300~km. The double phase LAr Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC) is known to provide excellent tracking and calorimetry performance that can outperform other techniques. An initial 20~kton LAr fiducial volume, as considered here, comparable to the fiducial mass of SuperKamiokande and NOvA, offers a new insight and an increase in sensitivity reach for many physics channels. A magnetized iron calorimeter with muon momentum and charge determination collects an independent neutrino sample, and serves as a tail catcher for CERN beam events occurring in the LAr target. The long baseline physics objectives comprise the precise investigation of all flavor oscillations ($ u_\mu\rightarrow u_\mu$, $ u_\mu\rightarrow u_\tau$, $ u_\mu\rightarrow u_e$) with neutrinos and antineutrinos, exploiting the energy spectrum information of the oscillation probability ($L/E$ method) in appearance and disappearance modes, to provide unambiguous sensitivity to oscillation parameters, and a stringent test of the 3-generation mixing. The existence of CP-violation will be tested explicitly, which is different from simply extracting the $\delta_{CP}$ violating phase from global fits of all available data. With an exposure of $2.25\times 10^{20}$~p.o.t. from the SPS at 400~GeV, a conclusive determination ($>5\sigma$~C.L.) of the neutrino mass hierarchy is possible for \emph{any} value of $\delta_{CP}$. Although limited by statistics in the initial configuration, the $L/E$ method also yields a clean measurement of the CP-violating phase. With $1\times 10^{21}$~p.o.t., the existence of CP-violation (CPV) can be demonstrated at the 90\%C.L. for $\sim 60\%$ of the $\delta_{CP}$ parameter space. This CPV-sensitivity is achievable in $\sim$12~years at the upgraded SPS. It improves further with the increased exposure resulting from longer running periods and/or an increase in beam power and far detector mass. With the chosen location in the deepest mine in Europe at $-1440$~m ($\sim$4000~m.w.e.), the already very large initial target mass provides an unique opportunity to observe new rare phenomena, independently of the CERN beam events. In the GeV range, evidence for Grand Unified Theories (GUT) can be searched for with nucleon decay signals. From 100~MeV to tens of GeV, the collection of thousands of atmospheric electron and muon neutrinos with good energy resolution and particle identification over a very large range of energies (SubGeV and MultiGeV) improves our understanding of this source and yields information on subleading oscillation effects, which provide additional and complementary sensitivity to the oscillation phenomenology including $\theta_{13}$, matter effects and possibly the CP-phase. At high energy, it allows an identification with high statistical significance and a study of $ u_\tau$ appearance in atmospheric events. Below 100~MeV, neutrinos from a new galactic supernova burst would be recorded with large statistics, addressing the astrophysics of the supernova and neutrino flavor oscillations through the SN and Earth matter. Neutrinos from relic supernovae could also be potentially detected, depending on their flux and prevailing backgrounds. LBNO can also potentially detect as-of-yet unknown sources of astrophysical neutrinos, like for instance those that could arise from annihilation processes of WIMP particles in astrophysical objects, and study their flavor composition. The plan described so far is augmented with a concrete upgrade path to evolve towards an ultimate volume observatory by additional units of increasingly larger masses. With a three-fold increase in exposure (defined as the product neutrino beam power $\times$ far detector target mass), CPV becomes accessible at $>3\sigma$~C.L. for 75\% of the $\delta_{CP}$ parameter space, assuming that all systematic errors can be controlled below the 5\% level. The LBNO far site at 2300~km from CERN could also represent the first step towards a Neutrino Factory project based on the decays of muons in the straight sections of a storage ring. Based on the expertise present at CERN and in European and in international research groups, and building upon the results of several years of EU-funded design studies, we are confident that the technology for the beam and detectors is sufficiently mature to allow for an early start to realizing the facility. We are calling on CERN to promptly support and engage in the prototyping of the near and far detector components, to investigate options for campaigns of detector performance characterization and calibration with test beams in the North Area, and engage in a collaborative effort with the LBNO Collaboration that should lead to a full engineering design of the CN2PY beam and to an LBNO Proposal by the end of 2014.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Planck 2018 results. VI. Cosmological parameters

Abstract: We present cosmological parameter results from the final full-mission Planck measurements of the cosmic microwave background (CMB) anisotropies, combining information from the temperature and polarization maps and the lensing reconstruction Compared to the 2015 results, improved measurements of large-scale polarization allow the reionization optical depth to be measured with higher precision, leading to significant gains in the precision of other correlated parameters Improved modelling of the small-scale polarization leads to more robust constraints on manyparameters,withresidualmodellinguncertaintiesestimatedtoaffectthemonlyatthe05σlevelWefindgoodconsistencywiththestandard spatially-flat6-parameter ΛCDMcosmologyhavingapower-lawspectrumofadiabaticscalarperturbations(denoted“base ΛCDM”inthispaper), from polarization, temperature, and lensing, separately and in combination A combined analysis gives dark matter density Ωch2 = 0120±0001, baryon density Ωbh2 = 00224±00001, scalar spectral index ns = 0965±0004, and optical depth τ = 0054±0007 (in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits) The angular acoustic scale is measured to 003% precision, with 100θ∗ = 10411±00003Theseresultsareonlyweaklydependentonthecosmologicalmodelandremainstable,withsomewhatincreasederrors, in many commonly considered extensions Assuming the base-ΛCDM cosmology, the inferred (model-dependent) late-Universe parameters are: HubbleconstantH0 = (674±05)kms−1Mpc−1;matterdensityparameterΩm = 0315±0007;andmatterfluctuationamplitudeσ8 = 0811±0006 We find no compelling evidence for extensions to the base-ΛCDM model Combining with baryon acoustic oscillation (BAO) measurements (and consideringsingle-parameterextensions)weconstraintheeffectiveextrarelativisticdegreesoffreedomtobe Neff = 299±017,inagreementwith the Standard Model prediction Neff = 3046, and find that the neutrino mass is tightly constrained toPmν < 012 eV The CMB spectra continue to prefer higher lensing amplitudesthan predicted in base ΛCDM at over 2σ, which pulls some parameters that affect thelensing amplitude away from the ΛCDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAOdataThejointconstraintwithBAOmeasurementsonspatialcurvatureisconsistentwithaflatuniverse, ΩK = 0001±0002Alsocombining with Type Ia supernovae (SNe), the dark-energy equation of state parameter is measured to be w0 = −103±003, consistent with a cosmological constant We find no evidence for deviations from a purely power-law primordial spectrum, and combining with data from BAO, BICEP2, and Keck Array data, we place a limit on the tensor-to-scalar ratio r0002 < 006 Standard big-bang nucleosynthesis predictions for the helium and deuterium abundances for the base-ΛCDM cosmology are in excellent agreement with observations The Planck base-ΛCDM results are in good agreement with BAO, SNe, and some galaxy lensing observations, but in slight tension with the Dark Energy Survey’s combined-probe results including galaxy clustering (which prefers lower fluctuation amplitudes or matter density parameters), and in significant, 36σ, tension with local measurements of the Hubble constant (which prefer a higher value) Simple model extensions that can partially resolve these tensions are not favoured by the Planck data

Planck 2018 results. VI. Cosmological parameters

Abstract: We present cosmological parameter results from the final full-mission Planck measurements of the CMB anisotropies. We find good consistency with the standard spatially-flat 6-parameter $\Lambda$CDM cosmology having a power-law spectrum of adiabatic scalar perturbations (denoted "base $\Lambda$CDM" in this paper), from polarization, temperature, and lensing, separately and in combination. A combined analysis gives dark matter density $\Omega_c h^2 = 0.120\pm 0.001$, baryon density $\Omega_b h^2 = 0.0224\pm 0.0001$, scalar spectral index $n_s = 0.965\pm 0.004$, and optical depth $\tau = 0.054\pm 0.007$ (in this abstract we quote $68\,\%$ confidence regions on measured parameters and $95\,\%$ on upper limits). The angular acoustic scale is measured to $0.03\,\%$ precision, with $100\theta_*=1.0411\pm 0.0003$. These results are only weakly dependent on the cosmological model and remain stable, with somewhat increased errors, in many commonly considered extensions. Assuming the base-$\Lambda$CDM cosmology, the inferred late-Universe parameters are: Hubble constant $H_0 = (67.4\pm 0.5)$km/s/Mpc; matter density parameter $\Omega_m = 0.315\pm 0.007$; and matter fluctuation amplitude $\sigma_8 = 0.811\pm 0.006$. We find no compelling evidence for extensions to the base-$\Lambda$CDM model. Combining with BAO we constrain the effective extra relativistic degrees of freedom to be $N_{\rm eff} = 2.99\pm 0.17$, and the neutrino mass is tightly constrained to $\sum m_ u< 0.12$eV. The CMB spectra continue to prefer higher lensing amplitudes than predicted in base -$\Lambda$CDM at over $2\,\sigma$, which pulls some parameters that affect the lensing amplitude away from the base-$\Lambda$CDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data. (Abridged)