Subjects -> ENGINEERING (Total: 2688 journals)
    - CHEMICAL ENGINEERING (229 journals)
    - CIVIL ENGINEERING (237 journals)
    - ELECTRICAL ENGINEERING (176 journals)
    - ENGINEERING (1325 journals)
    - ENGINEERING MECHANICS AND MATERIALS (452 journals)
    - HYDRAULIC ENGINEERING (56 journals)
    - INDUSTRIAL ENGINEERING (98 journals)
    - MECHANICAL ENGINEERING (115 journals)

ENGINEERING (1325 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 601 - 800 of 1205 Journals sorted alphabetically
International Journal of Quality Assurance in Engineering and Technology Education     Full-text available via subscription   (Followers: 3)
International Journal of Quality Engineering and Technology     Hybrid Journal   (Followers: 4)
International Journal of Quantum Information     Hybrid Journal   (Followers: 6)
International Journal of Rapid Manufacturing     Hybrid Journal   (Followers: 3)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access  
International Journal of Reliability, Quality and Safety Engineering     Hybrid Journal   (Followers: 14)
International Journal of Renewable Energy Technology     Hybrid Journal   (Followers: 8)
International Journal of Robust and Nonlinear Control     Hybrid Journal   (Followers: 10)
International Journal of Science and Innovative Technology     Open Access  
International Journal of Science Engineering and Advance Technology     Open Access  
International Journal of Sediment Research     Full-text available via subscription   (Followers: 2)
International Journal of Self-Propagating High-Temperature Synthesis     Hybrid Journal  
International Journal of Service Science, Management, Engineering, and Technology     Full-text available via subscription   (Followers: 2)
International Journal of Signal and Imaging Systems Engineering     Hybrid Journal  
International Journal of Six Sigma and Competitive Advantage     Hybrid Journal   (Followers: 4)
International Journal of Social Robotics     Hybrid Journal   (Followers: 3)
International Journal of Software Engineering and Knowledge Engineering     Hybrid Journal   (Followers: 6)
International Journal of Space Science and Engineering     Hybrid Journal   (Followers: 13)
International Journal of Speech Technology     Hybrid Journal   (Followers: 7)
International Journal of Spray and Combustion Dynamics     Full-text available via subscription   (Followers: 15)
International Journal of Student Project Reporting     Hybrid Journal   (Followers: 4)
International Journal of Surface Engineering and Interdisciplinary Materials Science     Full-text available via subscription   (Followers: 1)
International Journal of Surface Science and Engineering     Hybrid Journal   (Followers: 6)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 4)
International Journal of Sustainable Lighting     Open Access  
International Journal of Sustainable Manufacturing     Hybrid Journal   (Followers: 4)
International Journal of Systems and Service-Oriented Engineering     Full-text available via subscription  
International Journal of Systems Assurance Engineering and Management     Hybrid Journal  
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 6)
International Journal of Technoethics     Full-text available via subscription   (Followers: 2)
International Journal of Technology Management and Sustainable Development     Hybrid Journal   (Followers: 1)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 6)
International Journal of Telemedicine and Applications     Open Access   (Followers: 4)
International Journal of Thermal Sciences     Hybrid Journal   (Followers: 18)
International Journal of Thermodynamics     Open Access   (Followers: 15)
International Journal of Transportation Engineering     Open Access   (Followers: 2)
International Journal of Turbomachinery, Propulsion and Power     Open Access   (Followers: 23)
International Journal of Ultra Wideband Communications and Systems     Hybrid Journal  
International Journal of Vehicle Autonomous Systems     Hybrid Journal  
International Journal of Vehicle Design     Hybrid Journal   (Followers: 6)
International Journal of Vehicle Information and Communication Systems     Hybrid Journal   (Followers: 1)
International Journal of Vehicle Noise and Vibration     Hybrid Journal   (Followers: 6)
International Journal of Vehicle Safety     Hybrid Journal   (Followers: 3)
International Journal of Virtual Technology and Multimedia     Hybrid Journal   (Followers: 2)
International Journal of Wavelets, Multiresolution and Information Processing     Hybrid Journal  
International Journal on Artificial Intelligence Tools     Hybrid Journal   (Followers: 9)
International Journal on Smart Sensing and Intelligent Systems     Open Access  
International Nano Letters     Open Access   (Followers: 6)
International Review of Applied Sciences and Engineering     Full-text available via subscription  
International Scholarly Research Notices     Open Access   (Followers: 121)
International Scientific and Vocational Studies Journal     Open Access  
International Scientific Journal of Engineering and Technology (ISJET)     Open Access  
Inventions     Open Access  
Inventum     Open Access  
Inverse Problems in Science and Engineering     Hybrid Journal   (Followers: 3)
Investiga : TEC     Open Access  
Ionics     Hybrid Journal   (Followers: 2)
IPTEK The Journal for Technology and Science     Open Access  
Iranian Journal of Optimization     Open Access   (Followers: 2)
Iranian Journal of Science and Technology, Transactions A : Science     Hybrid Journal  
IRBM News     Full-text available via subscription  
Ironmaking & Steelmaking     Hybrid Journal   (Followers: 4)
ISA Transactions     Full-text available via subscription  
ISSS Journal of Micro and Smart Systems     Hybrid Journal   (Followers: 3)
IT Professional     Full-text available via subscription   (Followers: 24)
Iteckne     Open Access  
J-ENSITEC : Journal Of Engineering and Sustainable Technology     Open Access   (Followers: 4)
Johnson Matthey Technology Review     Open Access  
Journal of Advanced College of Engineering and Management     Open Access  
Journal of Advanced Joining Processes     Open Access  
Journal of Advanced Manufacturing Systems     Hybrid Journal   (Followers: 5)
Journal of Aerodynamics     Open Access   (Followers: 27)
Journal of Aerosol Science     Hybrid Journal   (Followers: 7)
Journal of Aerospace Engineering     Full-text available via subscription   (Followers: 66)
Journal of Alloys and Compounds     Hybrid Journal   (Followers: 16)
Journal of Analytical and Applied Pyrolysis     Hybrid Journal   (Followers: 5)
Journal of Analytical Science & Technology     Open Access   (Followers: 4)
Journal of Analytical Sciences, Methods and Instrumentation     Open Access   (Followers: 4)
Journal of Applied Engineering Sciences     Open Access  
Journal of Applied Physics     Hybrid Journal   (Followers: 69)
Journal of Applied Research and Technology     Open Access  
Journal of Applied Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Applied Sciences     Open Access   (Followers: 4)
Journal of Architectural and Engineering Research     Open Access   (Followers: 3)
Journal of Architectural Engineering     Full-text available via subscription   (Followers: 4)
Journal of Automation and Control     Open Access   (Followers: 9)
Journal of Aviation Technology and Engineering     Open Access   (Followers: 10)
Journal of Biological Dynamics     Open Access   (Followers: 1)
Journal of Biomedical Science     Open Access   (Followers: 4)
Journal of Biomolecular NMR     Hybrid Journal   (Followers: 6)
Journal of Biosciences     Open Access   (Followers: 1)
Journal of Building Pathology and Rehabilitation     Hybrid Journal  
Journal of Catalysis     Hybrid Journal   (Followers: 11)
Journal of Catalyst & Catalysis     Full-text available via subscription   (Followers: 2)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Journal of Chemical and Petroleum Engineering     Open Access   (Followers: 1)
Journal of China Coal Society     Open Access  
Journal of China Universities of Posts and Telecommunications     Full-text available via subscription  
Journal of Cleaner Production     Hybrid Journal   (Followers: 27)
Journal of Coastal and Riverine Flood Risk (JCRFR)     Open Access   (Followers: 1)
Journal of Cold Regions Engineering     Full-text available via subscription   (Followers: 3)
Journal of Combinatorial Designs     Hybrid Journal   (Followers: 4)
Journal of Combustion     Open Access   (Followers: 40)
Journal of Computational and Nonlinear Dynamics     Full-text available via subscription   (Followers: 6)
Journal of Computational and Theoretical Nanoscience     Full-text available via subscription  
Journal of Computational Biology     Hybrid Journal   (Followers: 9)
Journal of Computational Design and Engineering     Open Access   (Followers: 1)
Journal of Computational Electronics     Hybrid Journal   (Followers: 5)
Journal of Computational Multiphase Flows     Open Access   (Followers: 1)
Journal of Computing and Information Science in Engineering     Full-text available via subscription   (Followers: 1)
Journal of Coupled Systems and Multiscale Dynamics     Full-text available via subscription  
Journal of Dairy Science     Open Access   (Followers: 12)
Journal of Delta Urbanism     Open Access   (Followers: 2)
Journal of Display Technology     Hybrid Journal   (Followers: 3)
Journal of Dynamic Systems, Measurement, and Control     Full-text available via subscription   (Followers: 14)
Journal of Dynamical and Control Systems     Hybrid Journal   (Followers: 7)
Journal of Earthquake Engineering     Hybrid Journal   (Followers: 14)
Journal of Elasticity     Hybrid Journal   (Followers: 7)
Journal of Electroceramics     Hybrid Journal  
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 10)
Journal of Electronic Testing     Hybrid Journal   (Followers: 2)
Journal of Electronics Cooling and Thermal Control     Open Access   (Followers: 9)
Journal of Electrostatics     Hybrid Journal   (Followers: 2)
Journal of Energy Engineering     Full-text available via subscription   (Followers: 7)
Journal of Energy Resources Technology     Full-text available via subscription   (Followers: 4)
Journal of Engineering     Open Access  
Journal of Engineering     Open Access   (Followers: 1)
Journal of Engineering and Applied Science     Open Access  
Journal of Engineering and Technological Sciences     Open Access   (Followers: 2)
Journal of Engineering Design     Hybrid Journal   (Followers: 17)
Journal of Engineering Education     Hybrid Journal   (Followers: 7)
Journal of Engineering for Gas Turbines and Power     Full-text available via subscription   (Followers: 15)
Journal of Engineering Mathematics     Hybrid Journal   (Followers: 2)
Journal of Engineering Mechanics     Full-text available via subscription   (Followers: 16)
Journal of Engineering Physics and Thermophysics     Hybrid Journal   (Followers: 2)
Journal of Engineering Research     Open Access   (Followers: 1)
Journal of Engineering Research and Reports     Open Access  
Journal of Engineering Technology and Applied Sciences     Open Access  
Journal of Engineering Thermophysics     Hybrid Journal   (Followers: 4)
Journal of Engineering, Design and Technology     Hybrid Journal   (Followers: 17)
Journal of Engineering, Project, and Production Management     Open Access  
Journal of Environmental & Engineering Geophysics     Hybrid Journal   (Followers: 2)
Journal of Environmental Engineering     Full-text available via subscription   (Followers: 49)
Journal of Environmental Engineering and Landscape Management     Open Access   (Followers: 8)
Journal of Environmental Engineering and Science     Hybrid Journal   (Followers: 2)
Journal of Experimental Nanoscience     Hybrid Journal  
Journal of Fire Sciences     Hybrid Journal   (Followers: 6)
Journal of Flood Risk Management     Hybrid Journal   (Followers: 14)
Journal of Flow Control, Measurement & Visualization     Open Access   (Followers: 1)
Journal of Fluids Engineering     Full-text available via subscription   (Followers: 30)
Journal of Fourier Analysis and Applications     Hybrid Journal   (Followers: 3)
Journal of Fuel Cell Science and Technology     Full-text available via subscription   (Followers: 2)
Journal of Functional Analysis     Full-text available via subscription   (Followers: 3)
Journal of Fundamental and Applied Sciences     Open Access  
Journal of Geological Research     Open Access   (Followers: 1)
Journal of Geotechnical and Geoenvironmental Engineering     Full-text available via subscription   (Followers: 30)
Journal of Geotechnical Engineering     Full-text available via subscription   (Followers: 4)
Journal of Geovisualization and Spatial Analysis     Hybrid Journal  
Journal of Global Optimization     Hybrid Journal   (Followers: 6)
Journal of Graduate School of Natural and Applied Sciences of Mehmet Akif Ersoy University     Open Access  
Journal of Hazardous Materials Advances     Open Access  
Journal of Healthcare Engineering     Open Access   (Followers: 3)
Journal of Heat Transfer     Full-text available via subscription   (Followers: 66)
Journal of Humanitarian Engineering     Open Access   (Followers: 1)
Journal of Hydraulic Engineering     Full-text available via subscription   (Followers: 27)
Journal of Hyperspectral Remote Sensing     Open Access   (Followers: 23)
Journal of Imaging     Open Access   (Followers: 3)
Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 4)
Journal of Industrial Engineering and Management     Open Access   (Followers: 5)
Journal of Industrial Safety Engineering     Full-text available via subscription   (Followers: 6)
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 3)
Journal of Infrastructure Preservation and Resilience     Open Access   (Followers: 1)
Journal of Institute of Science and Technology     Open Access  
Journal of Intelligent and Connected Vehicles     Open Access   (Followers: 1)
Journal of Intelligent Systems : Theory and Applications     Open Access  
Journal of International Maritime Safety, Environmental Affairs, and Shipping     Open Access   (Followers: 1)
Journal of Iron and Steel Research International     Hybrid Journal   (Followers: 7)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 24)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of KONBiN     Open Access   (Followers: 4)
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 7)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 9)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 32)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 3)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 3)
Journal of Mechanical Design and Testing     Open Access   (Followers: 4)
Journal of Mechatronics     Full-text available via subscription   (Followers: 3)
Journal of Mega Infrastructure & Sustainable Development     Hybrid Journal  
Journal of Metallurgy     Open Access   (Followers: 8)
Journal of Mining Institute     Open Access  
Journal of Motor Behavior     Hybrid Journal   (Followers: 8)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 15)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription  
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 8)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 10)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 4)

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Similar Journals
Journal Cover
Journal of Fourier Analysis and Applications
Journal Prestige (SJR): 1.024
Citation Impact (citeScore): 1
Number of Followers: 3  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1531-5851 - ISSN (Online) 1069-5869
Published by Springer-Verlag Homepage  [2469 journals]
  • Completely Compact Herz–Schur Multipliers of Dynamical Systems

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      Abstract: Abstract We prove that if G is a discrete group and \((A,G,\alpha )\) is a C*-dynamical system such that the reduced crossed product \(A\rtimes _{r,\alpha } G\) possesses property (SOAP) then every completely compact Herz–Schur \((A,G,\alpha )\) -multiplier can be approximated in the completely bounded norm by Herz–Schur \((A,G,\alpha )\) -multipliers of finite rank. As a consequence, if G has the approximation property (AP) then the completely compact Herz–Schur multipliers of A(G) coincide with the closure of A(G) in the completely bounded multiplier norm. We study the class of invariant completely compact Herz–Schur multipliers of \(A\rtimes _{r,\alpha } G\) and provide a description of this class in the case of the irrational rotation algebra.
      PubDate: 2022-05-13
       
  • An Analogy of the Carleson–Hunt Theorem with Respect to Vilenkin
           Systems

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      Abstract: Abstract In this paper we discuss and prove an analogy of the Carleson–Hunt theorem with respect to Vilenkin systems. In particular, we use the theory of martingales and give a new and shorter proof of the almost everywhere convergence of Vilenkin–Fourier series of \(f\in L_p(G_m)\) for \(p>1\) in case the Vilenkin system is bounded. Moreover, we also prove sharpness by stating an analogy of the Kolmogorov theorem for \(p=1\) and construct a function \(f\in L_1(G_m)\) such that the partial sums with respect to Vilenkin systems diverge everywhere.
      PubDate: 2022-05-13
       
  • On the Boundedness of the Hilbert Transform from Weighted Sobolev Space to
           Weighted Lebesgue Space

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      Abstract: Abstract Under some restrictions on weight functions we obtain sufficient conditions for the boundedness of the Hilbert transform from weighted Sobolev space of the first order on the semi-axis to weighted Lebesgue space.
      PubDate: 2022-05-09
       
  • A Proof of Fatou’s Interpolation Theorem

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      Abstract: Abstract For Fatou’s interpolation theorem of 1906 we suggest a new elementary proof.
      PubDate: 2022-05-05
       
  • Restriction Estimates in a Conical Singular Space: Wave Equation

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      Abstract: Abstract We study the restriction estimates in a class of conical singular space \(X=C(Y)=(0,\infty )_r\times Y\) with the metric \(g=\mathrm {d}r^2+r^2h\) , where the cross section Y is a compact \((n-1)\) -dimensional closed Riemannian manifold (Y, h). Let \(\Delta _g\) be the Friedrichs extension positive Laplacian on X, and consider the operator \(\mathcal {L}_V=\Delta _g+V\) with \(V=V_0r^{-2}\) , where \(V_0(\theta )\in \mathcal {C}^\infty (Y)\) is a real function such that the operator \(\Delta _h+V_0+(n-2)^2/4\) is positive. In the present paper, we prove a type of modified restriction estimates for the solutions of wave equation associated with \(\mathcal {L}_V\) . The smallest positive eigenvalue of the operator \(\Delta _h+V_0+(n-2)^2/4\) plays an important role in the result. As an application, for independent of interests, we prove local energy estimates and Keel–Smith–Sogge estimates for the wave equation in this setting.
      PubDate: 2022-05-03
       
  • Singular and Fractional Integral Operators on Weighted Local Morrey Spaces

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      Abstract: Abstract We obtain a characterization of the weighted inequalities for the Riesz transforms on weighted local Morrey spaces. The condition is sufficient for the boundedness on the same spaces of all Calderón–Zygmund operators suitably defined on the functions of the space. In the case of the fractional maximal operator and the fractional integral we obtain a characterization valid for exponents satisfying the Sobolev relation. For power weights we get sharp results for these operators in the usual versions of weighted Morrey spaces, neither restricted to the Sobolev relation of the exponents nor to the one-weighted setting.
      PubDate: 2022-04-28
       
  • Operating Functions on $$A^q_s({{\mathbf {T}}})$$ A s q ( T )

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      Abstract: Abstract Let \(A^q_s({{\mathbf {T}}})\) denote the space of all Lebesgue integrable functions f on the torus \({\mathbf {T}}\) such that \(\sum _{m \in {{\mathbf {Z}}}} \widehat{f}(m) ^q \langle m \rangle ^{sq} < \infty \) , where \(\{ \widehat{f}(m) \}_{m \in {{\mathbf {Z}}}}\) denote the Fourier coefficients of f. We consider necessary and sufficient conditions for all functions \(F \in A^1_\beta ({{\mathbf {T}}})\) to operate on all real-valued functions in \(A^q_s({{\mathbf {T}}})\) .
      PubDate: 2022-04-28
       
  • Correction to: An Optimal Multiplier Theorem for Grushin Operators in the
           Plane, II

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      PubDate: 2022-04-25
       
  • Strict Positive Definiteness of Convolutional and Axially Symmetric
           Kernels on d-Dimensional Spheres

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      Abstract: Abstract The paper introduces new sufficient conditions of strict positive definiteness for kernels on d-dimensional spheres which are not radially symmetric but possess specific coefficient structures. The results use the series expansion of the kernel in spherical harmonics. The kernels either have a convolutional form or are axially symmetric with respect to one axis. The given results on convolutional kernels generalise the result derived by Chen et al. (Proc Am Math Soc 131:2733–2740, 2003) for radial kernels.
      PubDate: 2022-04-18
       
  • On Foundational Discretization Barriers in STFT Phase Retrieval

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      Abstract: Abstract We prove that there exists no window function \(g \in {L^2(\mathbb {R})}\) and no lattice \({\mathcal {L}} \subset \mathbb {R}^2\) such that every \(f \in {L^2(\mathbb {R})}\) is determined up to a global phase by spectrogram samples \( V_gf({\mathcal {L}}) \) where \(V_gf\) denotes the short-time Fourier transform of f with respect to g. Consequently, the forward operator $$\begin{aligned} f \mapsto V_gf({\mathcal {L}}) \end{aligned}$$ mapping a square-integrable function to its spectrogram samples on a lattice is never injective on the quotient space with \(f \sim h\) identifying two functions which agree up to a multiplicative constant of modulus one. We will further elaborate this result and point out that under mild conditions on the lattice \({\mathcal {L}}\) , functions which produce identical spectrogram samples but do not agree up to a unimodular constant can be chosen to be real-valued. The derived results highlight that in the discretization of the STFT phase retrieval problem from lattice measurements, a prior restriction of the underlying signal space to a proper subspace of \({L^2(\mathbb {R})}\) is inevitable.
      PubDate: 2022-04-04
       
  • Dot-Product Sets and Simplices Over Finite Rings

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      Abstract: Abstract In this paper, we study dot-product sets and k-simplices in \(\mathbb {Z}_n^d\) for odd n,  where \(\mathbb {Z}_n\) is the ring of residues modulo n. We show that if E is sufficiently large then the dot-product set of E covers the whole ring. In higher dimensional cases, if E is sufficiently large then the set of simplices and the set of dot-product simplices determined by E, up to congurence, have positive densities.
      PubDate: 2022-03-30
       
  • Heisenberg Uniqueness Pairs for the Finitely Many Parallel Lines with an
           Irregular Gap

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      Abstract: Abstract Let \(X(\Gamma )\) be the space of all finite Borel measure \(\mu \) in \(\mathbb R^2\) which is supported on the smooth curve \(\Gamma \) and absolutely continuous with respect to the arc length on \(\Gamma \) . For \(\Lambda \subset \mathbb R^2,\) the pair \(\left( \Gamma , \Lambda \right) \) is called a Heisenberg uniqueness pair for \(X(\Gamma )\) if any \(\mu \in X(\Gamma )\) satisfies \(\hat{\mu }\vert _\Lambda =0,\) implies \(\mu =0.\) We prove a characterization of the Heisenberg uniqueness pairs corresponding to finitely many parallel lines with an irregular gap. We observe that the size of the determining sets \(\Lambda \) for \(X(\Gamma )\) depends on the number of lines and their irregular distribution that further relates to a phenomenon of the interlacing of certain trigonometric polynomials.
      PubDate: 2022-03-30
       
  • Exterior Dirichlet and Neumann Problems and the Linked Ergodic Inverse
           Problems in the Entire Space

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      Abstract: Abstract The paper is mainly concerned with the interconnection of the boundary behaviour of the solutions of the exterior Dirichlet and Neumann problems of harmonic analysis for the unit disk in \({\mathbb {R}}^2\) and the unit ball in \({\mathbb {R}}^3\) with the corresponding behaviour of the associated ergodic inverse problems for the entire space. The basis is the theory of semigroups of linear operators mapping a Banach space X into itself. The classical one-parameter theory for semigroups applies in the present particular applications, actually for \(X= L^2_{2\pi }\) in case of the unit disk, and \(X=L^2(S)\) in the three dimensional setting, S being the unit sphere in \({\mathbb {R}}^3\) . Another tool is a Drazin-like inverse operator B for the infinitesimal generator A of a semigroup that arises naturally in ergodic theory. This operator B is a closed, not necessarily bounded, operator. It was introduced in a paper with Butzer and Westphal (Indiana Univ Math J 20:1163–1174, 1970/1971) and extended to a generalized setting with Butzer and Koliha (J Oper Theory 62:297–326, 2009).
      PubDate: 2022-03-29
       
  • Derandomized Compressed Sensing with Nonuniform Guarantees for $$\ell _1$$
           ℓ 1 Recovery

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      Abstract: Abstract In compressed sensing, the sensing matrices of minimal sample complexity are constructed with the help of randomness. Over 13 years ago, Tao (Open question: deterministic UUP matrices. https://terrytao.wordpress.com/2007/07/02/open-question-deterministic-uup-matrices/) posed the notoriously difficult problem of derandomizing these sensing matrices. While most work in this vein has been in the setting of explicit deterministic matrices with uniform guarantees, the present paper focuses on explicit random matrices of low entropy with non-uniform guarantees. Specifically, we extend the techniques of Hügel et al. (Found Comput Math 14:115–150, 2014) to show that for every \(\delta \in (0,1]\) , there exists an explicit random \(m\times N\) partial Fourier matrix A with \(m\le C_1(\delta )s\log ^{4/\delta }(N/\epsilon )\) and entropy at most \(C_2(\delta )s^\delta \log ^5(N/\epsilon )\) such that for every s-sparse signal \(x\in {\mathbb {C}}^N\) , there exists an event of probability at least \(1-\epsilon \) over which x is the unique minimizer of \(\Vert z\Vert _1\) subject to \(Az=Ax\) . The bulk of our analysis uses tools from decoupling to estimate the extreme singular values of the submatrix of A whose columns correspond to the support of x.
      PubDate: 2022-03-29
       
  • Partial Data Problems and Unique Continuation in Scalar and Vector Field
           Tomography

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      Abstract: Abstract We prove that if P(D) is some constant coefficient partial differential operator and f is a scalar field such that P(D)f vanishes in a given open set, then the integrals of f over all lines intersecting that open set determine the scalar field uniquely everywhere. This is done by proving a unique continuation property of fractional Laplacians which implies uniqueness for the partial data problem. We also apply our results to partial data problems of vector fields.
      PubDate: 2022-03-26
       
  • Compactness of Commutators of Integral Operators with Functions in
           Campanato Spaces on Orlicz-Morrey Spaces

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      Abstract: Abstract We consider the commutators [b, T] and \([b,I_{\rho }]\) , where T is a Calderón–Zygmund operator, \(I_{\rho }\) is a generalized fractional integral operator and b is a function in the closure of \(C^{\infty }_{\mathrm {comp}}(\mathbb {R}^n)\) with respect to generalized Campanato spaces. We give a necessary and sufficient condition for the compactness of [b, T] and \([b,I_{\rho }]\) on Orlicz-Morrey spaces. The Orlicz-Morrey spaces unify Orlicz and Morrey spaces, and the Campanato spaces unify \(\mathrm {BMO}\) and Lipschitz spaces. Therefore, our results contain many previous results as corollaries.
      PubDate: 2022-03-23
       
  • An Optimal Multiplier Theorem for Grushin Operators in the Plane, II

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      Abstract: Abstract In a previous work we proved a spectral multiplier theorem of Mihlin–Hörmander type for two-dimensional Grushin operators \(-\partial _x^2 - V(x) \partial _y^2\) , where V is a doubling single-well potential, yielding the surprising result that the optimal smoothness requirement on the multiplier is independent of V. Here we refine this result, by replacing the \(L^\infty \) -Sobolev condition on the multiplier with a sharper \(L^2\) -Sobolev condition. As a consequence, we obtain the sharp range of \(L^1\) -boundedness for the associated Bochner–Riesz means. The key new ingredient of the proof is a precise pointwise estimate in the transition region for eigenfunctions of one-dimensional Schrödinger operators with doubling single-well potentials.
      PubDate: 2022-03-22
       
  • Extrapolation and the Boundedness in Grand Variable Exponent Lebesgue
           Spaces Without Assuming the Log-Hölder Continuity Condition, and
           Applications

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      Abstract: Abstract The boundedness of the Hardy–Littlewood maximal operator, and the weighted extrapolation in grand variable exponent Lebesgue spaces are established provided that Hardy–Littlewood maximal operator is bounded in appropriate variable exponent Lebesgue space. Moreover, we give some bounds of the norm of the Hardy–Littlewood maximal operator in these spaces. As corollaries, we have appropriate norm inequalities and the boundedness of operators of Harmonic Analysis such as maximal and sharp maximal functions; Calderón–Zygmund singular integrals, commutators of singular integrals in grand variable exponent Lebesgue spaces. Finally, applying the boundedness results of integral operators of Harmonic Analysis, we have the direct and inverse theorems on the approximation of \(2\pi \) -periodic functions by trigonometric polynomials in the framework of grand variable exponent Lebesgue spaces.
      PubDate: 2022-03-21
       
  • On the Stability of Fourier Phase Retrieval

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      Abstract: Abstract Phase retrieval is concerned with recovering a function f from the absolute value of its Fourier transform \( {\widehat{f}} \) . We study the stability properties of this problem in Lebesgue spaces. Our main results shows that $$\begin{aligned} \Vert f-g\Vert _{L^2({\mathbb {R}}^n)} \le 2\cdot \Vert {\widehat{f}} - {\widehat{g}} \Vert _{L^2({\mathbb {R}}^n)} + h_f\left( \Vert f-g\Vert ^{}_{L^p({\mathbb {R}}^n)}\right) + J({\widehat{f}}, {\widehat{g}}), \end{aligned}$$ where \(1 \le p < 2\) , \(h_f\) is an explicit nonlinear function depending on the smoothness of f and J is an explicit term capturing the invariance under translations. A noteworthy aspect is that the stability is phrased in terms of \(L^p\) for \(1 \le p < 2\) : in this region \(L^p\) cannot be used to control \(L^2\) , our stability estimate has the flavor of an inverse Hölder inequality. It seems conceivable that the estimate is optimal up to constants.
      PubDate: 2022-03-21
       
  • Approximation Properties of the Double Fourier Sphere Method

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      Abstract: Abstract We investigate analytic properties of the double Fourier sphere (DFS) method, which transforms a function defined on the two-dimensional sphere to a function defined on the two-dimensional torus. Then the resulting function can be written as a Fourier series yielding an approximation of the original function. We show that the DFS method preserves smoothness: it continuously maps spherical Hölder spaces into the respective spaces on the torus, but it does not preserve spherical Sobolev spaces in the same manner. Furthermore, we prove sufficient conditions for the absolute convergence of the resulting series expansion on the sphere as well as results on the speed of convergence.
      PubDate: 2022-03-21
       
 
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