Kooperativer Bibliotheksverbund

UID:

Format: 1 Online-Ressource (31 Seiten)

ISSN: 0067-0049 , 0067-0049

Content: We calibrate spectrophotometric optical spectra of 32 stars commonly used as standard stars, referenced to 14 stars already on the Hubble Space Telescope–based CALSPEC flux system. Observations of CALSPEC and non-CALSPEC stars were obtained with the SuperNova Integral Field Spectrograph over the wavelength range 3300–9400 Å as calibration for the Nearby Supernova Factory cosmology experiment. In total, this analysis used 4289 standard-star spectra taken on photometric nights. As a modern cosmology analysis, all presubmission methodological decisions were made with the flux scale and external comparison results blinded. The large number of spectra per star allows us to treat the wavelength-by-wavelength calibration for all nights simultaneously with a Bayesian hierarchical model, thereby enabling a consistent treatment of the Type Ia supernova cosmology analysis and the calibration on which it critically relies. We determine the typical per-observation repeatability (median 14 mmag for exposures ≳5 s), the Maunakea atmospheric transmission distribution (median dispersion of 7 mmag with uncertainty 1 mmag), and the scatter internal to our CALSPEC reference stars (median of 8 mmag). We also check our standards against literature filter photometry, finding generally good agreement over the full 12 mag range. Overall, the mean of our system is calibrated to the mean of CALSPEC at the level of ∼3 mmag. With our large number of observations, careful cross-checks, and 14 reference stars, our results are the best calibration yet achieved with an integral-field spectrograph, and among the best calibrated surveys.

Content: Peer Reviewed

In: London : Institute of Physics Publ., 263,1, 0067-0049

Language: English

DOI: 10.3847/1538-4365/ac7b7f

DOI: 10.18452/26424

URN: urn:nbn:de:kobv:11-110-18452/27104-7

URL: Volltext  (kostenfrei)

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Format: 1 Online-Ressource (17 Seiten)

ISSN: 0004-637X , 0004-637X

Content: We construct a physically parameterized probabilistic autoencoder (PAE) to learn the intrinsic diversity of Type Ia supernovae (SNe Ia) from a sparse set of spectral time series. The PAE is a two-stage generative model, composed of an autoencoder that is interpreted probabilistically after training using a normalizing flow. We demonstrate that the PAE learns a low-dimensional latent space that captures the nonlinear range of features that exists within the population and can accurately model the spectral evolution of SNe Ia across the full range of wavelength and observation times directly from the data. By introducing a correlation penalty term and multistage training setup alongside our physically parameterized network, we show that intrinsic and extrinsic modes of variability can be separated during training, removing the need for the additional models to perform magnitude standardization. We then use our PAE in a number of downstream tasks on SNe Ia for increasingly precise cosmological analyses, including the automatic detection of SN outliers, the generation of samples consistent with the data distribution, and solving the inverse problem in the presence of noisy and incomplete data to constrain cosmological distance measurements. We find that the optimal number of intrinsic model parameters appears to be three, in line with previous studies, and show that we can standardize our test sample of SNe Ia with an rms of 0.091 ± 0.010 mag, which corresponds to 0.074 ± 0.010 mag if peculiar velocity contributions are removed. Trained models and codes are released at https://github.com/georgestein/suPAErnova.

Content: Peer Reviewed

In: The astrophysical journal, London : Institute of Physics Publ., 935,2022,1, 0004-637X

Language: English

DOI: 10.3847/1538-4357/ac7c08

DOI: 10.18452/26486

URN: urn:nbn:de:kobv:11-110-18452/27168-6

URL: Volltext  (kostenfrei)

UID:

Format: 1 online resource (IX, 466 p.) : , Num. figs.

Edition: Reprint 2020

ISBN: 9783112318973 , 9783110637199

Note: Frontmatter -- , CONTENTS -- , Preface -- , 65-th Anniversary of Prof. Drumi Bainov -- , Construction of Systems of Partial Differential Equations and Their Solutions -- , Inverse Spectral Problem for the Differential Equation of the Second Order with Singularity -- , Inverse Problem for the Sturm-Liouville According to a Spectrum and Normalizing -- , On the Range and Inversion of Certain Unsymmetric Operators -- , Impulsive Hamilton-Jacobi Equations for Hybrid Control Systems -- , Numerical Solution of Multi-Time Dynamic Programming Equations -- , Overdetermined Differential Systems in Spaces of (Small) Gevrey Functions -- , Applications of Stochastic Differential Equations to Population Growth -- , Nonlocal Evolution Problems -- , Matrix Semigroups and Differential Equations: Ergodism and Asymptotic Behaviour of Solutions with or without Impulses, a Survey (2) -- , Schwarz Algorithms for Nonconforming and Mixed Methods for Second-Order Problems -- , Local Mesh Refinement for Degenerate Two-Phase Incompressible Flow Problems -- , The Existence of Infinitely Many Solutions of a Nonlinear Wave Equation -- , The Approximation of Continuous Periodic Functions by Means of Extrapolation Techniques for the De La Valle'e Poussin Operator -- , Variational Inequalities, Equivalent Optimization Problems and Associated Lagrangean Function -- , Studying the Numerical Properties of Solvers for Systems of Nonlinear Equations -- , Superlinear Convergence of Asynchronous Waveform Relaxation Methods for Nonlinear ODEs -- , A Discretization Scheme and Error Estimate for First-Order Systems and Elliptic Problems -- , Stability Estimates for a Boundary Identification Problem in a Thin Domain -- , Partial Hölder Continuity Results for Solution of non Linear non Variational Elliptic Systems with Limit Controlled Growth -- , Applications of the Lyapunov Direct Method for Stability Investigations of Some Functional Differential Equations -- , On Global Weak Solutions of a Nonlinear Evolution Equation in Noncylindrical Domain J. Ferreira and M.A. Rojas-Medar -- , Lifting Theory and its Application to Quantum Amplifier Processes -- , Tangential Oblique Derivative Problem for Nonlinear Elliptic Discontinuous Operators in the Plane -- , Life Span of Solutions for Non Linear Cauchy Problem -- , Approximation of the McKendrick-Von Foester Equation for Population Growth -- , Global Asymptotic Stability of FitzHugh-Nagumo System -- , Oscillation Results for Semilinear Elliptic Equations -- , A Simple Model of the Ocean with Eastern Boundary Slope Current -- , New Algorithm of Curve Fitting for Non Decreasing Time Series Data -- , The Asymptotic Distribution for the Eigenfunctions of the Sturm-Liouville Equation -- , Existence of Group Invariant Solutions of a Certain Semilinear Elliptic Equation -- , Structured Programming Diagram PAD, PDE Solver, and Formation of Planetary System -- , Coefficients of an Asymptotic Expansion of logDet for Elliptic Operators with Parameter -- , Accurate Splatting of Octrees -- , Singular Linear ODEs -- , Fine Regularity for Nonlinear Nonvariational Parabolic Systems Overlapping Multi-Subdomain Asynchronous Fixed Point Methods for Elliptic Boundary Value Problems -- , Overlapping Multi-Subdomain Asynchronous Fixed Point Methods for Elliptic Boundary Value Problems -- , Two-Step Variable Metric Conjugate Gradient Algorithms -- , Nonsmooth Variational Methods and Applications to Discontinuous Boundary Value Problems -- , Mean Value Properties for the Wave Equation -- , A Note on the Solutions of r"(x)r(x) = g(x)r'2(x) -- , Properties of General Elementary Matrices in Mathematical Science -- , Oblique Derivative Problem in Morrey Spaces -- , Applying Probabilistic Neural Networks to the Multifont Recognition Problem -- , A Nested then Coupled Mediterranean Sea Layer-Level Model -- , One Phenomenon for the Wave Equation in R 3 -- , Blow Up of the Solutions for Quasilinear Hyperbolic Systems and Application to the Nonlinear Vibrating String Equation -- , Regularity of the First Derivatives of the Solutions of a Class of Linear Elliptic Equations of Second Order with Discontinuous Coefficients -- , Fractal Geometry for Natural-Looking Tree Generation -- , Exact Solutions of the Navier-Stokes Equations -- , Remarks on the N-Body Problem in Celestial Mechanics -- , Toeplitz-Theorem for Set-Valued Sequences in Banach-Spaces -- , Mixed Problem for a Damped Quasilinear Wave Equation -- , Stability of Integral Manifolds of Neutral Functional Differential Equations -- , Numerical Accuracy of Dynamical System Integration -- , Approximations of a General Class of Quantum-Mechanical One-Dimensional Point Interactions by Local Self-Adjoint Interactions -- , An Exponentially-Fitted Finite Difference Method for the Numerical Solution of Differential Equations with Engineering Applications -- , L ∞ -Estimates for Strong Solutions to Quasilinear Elliptic Equations -- , On Convolutional Decompositions of the Generalized Inverse Gaussian Distributions and the Student t-Distributions -- , The Complete Ducks Not Satisfying S 1 -- , Oscillation Criteria for Linear Differential Equations -- , Connection Between Differential Equations and Differential Geometry -- , Errors in Iteration Points in Oscillatory State for Systems of Algebraic Equations -- , Equicontinuity Domains and Runge Domains -- , Riemann Conditions for Quasi-Abelian Varieties -- , An Approximation of the Functional of a Free Boundary Problem -- , A Mathematical Expression of Vertical Distribution of Annual Ring Widths of Trees Based on Height Growth and Inflow of Solute Carbohydrate from Roots , Issued also in print. , Mode of access: Internet via World Wide Web. , In English.

In: DGBA Mathematics - 1990 - 1999, De Gruyter, 9783110637199

Additional Edition: ISBN 9783112307700

Language: English

DOI: 10.1515/9783112318973

URL: https://doi.org/10.1515/9783112318973

URL: https://www.degruyter.com/isbn/9783112318973

URL: Cover

UID:

Format: 1 online resource (IX, 466 p.) : , Num. figs.

Edition: Reprint 2020

ISBN: 9783112318973

Note: Frontmatter -- , CONTENTS -- , Preface -- , 65-th Anniversary of Prof. Drumi Bainov -- , Construction of Systems of Partial Differential Equations and Their Solutions -- , Inverse Spectral Problem for the Differential Equation of the Second Order with Singularity -- , Inverse Problem for the Sturm-Liouville According to a Spectrum and Normalizing -- , On the Range and Inversion of Certain Unsymmetric Operators -- , Impulsive Hamilton-Jacobi Equations for Hybrid Control Systems -- , Numerical Solution of Multi-Time Dynamic Programming Equations -- , Overdetermined Differential Systems in Spaces of (Small) Gevrey Functions -- , Applications of Stochastic Differential Equations to Population Growth -- , Nonlocal Evolution Problems -- , Matrix Semigroups and Differential Equations: Ergodism and Asymptotic Behaviour of Solutions with or without Impulses, a Survey (2) -- , Schwarz Algorithms for Nonconforming and Mixed Methods for Second-Order Problems -- , Local Mesh Refinement for Degenerate Two-Phase Incompressible Flow Problems -- , The Existence of Infinitely Many Solutions of a Nonlinear Wave Equation -- , The Approximation of Continuous Periodic Functions by Means of Extrapolation Techniques for the De La Valle'e Poussin Operator -- , Variational Inequalities, Equivalent Optimization Problems and Associated Lagrangean Function -- , Studying the Numerical Properties of Solvers for Systems of Nonlinear Equations -- , Superlinear Convergence of Asynchronous Waveform Relaxation Methods for Nonlinear ODEs -- , A Discretization Scheme and Error Estimate for First-Order Systems and Elliptic Problems -- , Stability Estimates for a Boundary Identification Problem in a Thin Domain -- , Partial Hölder Continuity Results for Solution of non Linear non Variational Elliptic Systems with Limit Controlled Growth -- , Applications of the Lyapunov Direct Method for Stability Investigations of Some Functional Differential Equations -- , On Global Weak Solutions of a Nonlinear Evolution Equation in Noncylindrical Domain J. Ferreira and M.A. Rojas-Medar -- , Lifting Theory and its Application to Quantum Amplifier Processes -- , Tangential Oblique Derivative Problem for Nonlinear Elliptic Discontinuous Operators in the Plane -- , Life Span of Solutions for Non Linear Cauchy Problem -- , Approximation of the McKendrick-Von Foester Equation for Population Growth -- , Global Asymptotic Stability of FitzHugh-Nagumo System -- , Oscillation Results for Semilinear Elliptic Equations -- , A Simple Model of the Ocean with Eastern Boundary Slope Current -- , New Algorithm of Curve Fitting for Non Decreasing Time Series Data -- , The Asymptotic Distribution for the Eigenfunctions of the Sturm-Liouville Equation -- , Existence of Group Invariant Solutions of a Certain Semilinear Elliptic Equation -- , Structured Programming Diagram PAD, PDE Solver, and Formation of Planetary System -- , Coefficients of an Asymptotic Expansion of logDet for Elliptic Operators with Parameter -- , Accurate Splatting of Octrees -- , Singular Linear ODEs -- , Fine Regularity for Nonlinear Nonvariational Parabolic Systems Overlapping Multi-Subdomain Asynchronous Fixed Point Methods for Elliptic Boundary Value Problems -- , Overlapping Multi-Subdomain Asynchronous Fixed Point Methods for Elliptic Boundary Value Problems -- , Two-Step Variable Metric Conjugate Gradient Algorithms -- , Nonsmooth Variational Methods and Applications to Discontinuous Boundary Value Problems -- , Mean Value Properties for the Wave Equation -- , A Note on the Solutions of r"(x)r(x) = g(x)r'2(x) -- , Properties of General Elementary Matrices in Mathematical Science -- , Oblique Derivative Problem in Morrey Spaces -- , Applying Probabilistic Neural Networks to the Multifont Recognition Problem -- , A Nested then Coupled Mediterranean Sea Layer-Level Model -- , One Phenomenon for the Wave Equation in R 3 -- , Blow Up of the Solutions for Quasilinear Hyperbolic Systems and Application to the Nonlinear Vibrating String Equation -- , Regularity of the First Derivatives of the Solutions of a Class of Linear Elliptic Equations of Second Order with Discontinuous Coefficients -- , Fractal Geometry for Natural-Looking Tree Generation -- , Exact Solutions of the Navier-Stokes Equations -- , Remarks on the N-Body Problem in Celestial Mechanics -- , Toeplitz-Theorem for Set-Valued Sequences in Banach-Spaces -- , Mixed Problem for a Damped Quasilinear Wave Equation -- , Stability of Integral Manifolds of Neutral Functional Differential Equations -- , Numerical Accuracy of Dynamical System Integration -- , Approximations of a General Class of Quantum-Mechanical One-Dimensional Point Interactions by Local Self-Adjoint Interactions -- , An Exponentially-Fitted Finite Difference Method for the Numerical Solution of Differential Equations with Engineering Applications -- , L ∞ -Estimates for Strong Solutions to Quasilinear Elliptic Equations -- , On Convolutional Decompositions of the Generalized Inverse Gaussian Distributions and the Student t-Distributions -- , The Complete Ducks Not Satisfying S 1 -- , Oscillation Criteria for Linear Differential Equations -- , Connection Between Differential Equations and Differential Geometry -- , Errors in Iteration Points in Oscillatory State for Systems of Algebraic Equations -- , Equicontinuity Domains and Runge Domains -- , Riemann Conditions for Quasi-Abelian Varieties -- , An Approximation of the Functional of a Free Boundary Problem -- , A Mathematical Expression of Vertical Distribution of Annual Ring Widths of Trees Based on Height Growth and Inflow of Solute Carbohydrate from Roots , Issued also in print. , In English.

Additional Edition: ISBN 9783112307700

Language: English

URL: https://www.degruyter.com/isbn/9783112318973

URL: https://www.degruyter.com/isbn/9783112318973