Results 41 to 50 of about 76,006 (191)
Self‐Similar Blowup for the Cubic Schrödinger Equation
Communications on Pure and Applied Mathematics, EarlyView.ABSTRACT We give a rigorous proof for the existence of a finite‐energy, self‐similar solution to the focusing cubic Schrödinger equation in three spatial dimensions. The proof is computer‐assisted and relies on a fixed point argument that shows the existence of a solution in the vicinity of a numerically constructed approximation.
Roland Donninger, Birgit Schörkhuber
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Communications on Pure and Applied Mathematics, EarlyView.ABSTRACT The leading‐order asymptotic behavior of the solution of the Cauchy initial‐value problem for the Benjamin–Ono equation in L2(R)$L^2(\mathbb {R})$ is obtained explicitly for generic rational initial data u0$u_0$. An explicit asymptotic wave profile uZD(t,x;ε)$u^\mathrm{ZD}(t,x;\epsilon)$ is given, in terms of the branches of the multivalued ...
Elliot Blackstone +3 more
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Stability of Viscous Three‐Dimensional Stratified Couette Flow via Dispersion and Mixing
Communications on Pure and Applied Mathematics, EarlyView.ABSTRACT This article explores the stability of stratified Couette flow in the viscous 3d$3d$ Boussinesq equations. In this system, mixing effects arise from the shearing background, and gravity acts as a restoring force leading to dispersive internal gravity waves.
Michele Coti Zelati +2 more
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Stability Bounds for the Generalized Kadanoff‐Baym Ansatz in the Holstein Dimer
Contributions to Plasma Physics, EarlyView.ABSTRACT Predicting real‐time dynamics in correlated systems is demanding: exact two‐time Green's function methods are accurate but often too costly, while the Generalized Kadanoff‐Baym Ansatz (GKBA) offers time‐linear propagation at the risk of uncontrolled behavior. We examine when and why GKBA fails in a minimal yet informative setting, the Holstein
Oscar Moreno Segura +2 more
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Earthquake Engineering &Structural Dynamics, EarlyView.ABSTRACT Iterative solvers are advantageous for handling nonlinear structural analysis problems. The iterative solvers often require updating the stiffness matrix, which limits their application in static and pseudo‐dynamic hybrid simulations because: (1) updating the stiffness matrix of a system involving a physical specimen is challenging; (2 ...
Junyan Xiao, Oh‐Sung Kwon, Evan Bentz
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Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver
International Journal for Numerical Methods in Fluids, EarlyView.A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
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Revisiting EWMA in High‐Frequency‐Based Portfolio Optimization: A Comparative Assessment
Journal of Applied Econometrics, EarlyView.ABSTRACT This paper compares the statistical and economic performance of state‐of‐the‐art high‐frequency (HF) based multivariate volatility models with a simpler, widely used alternative, the Exponentially Weighted Moving Average (EWMA) filter. Using over two decades of 100 U.S.
Laura Capera Romero, Anne Opschoor
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Journal of Applied Econometrics, EarlyView.ABSTRACT We present four novel tests of equal predictive accuracy and encompassing á Pitarakis (2023, 2025) for factor‐augmented regressions. Factors are estimated using cross‐section averages (CAs) of grouped series and our theoretical findings are empirically relevant: asymptotic normality, robustness to an overspecification of the number of factors,
Alessandro Morico, Ovidijus Stauskas
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Journal of Magnetic Resonance Imaging, EarlyView.ABSTRACT Alzheimer's disease (AD) is one of the most common neurological disorders affecting older adults, with approximately 7.2 million cases only in the United States. This number is projected to increase to 13.8 million in the United States by 2060, leading to increased expenditures for healthcare, long‐term care and hospice services. Consequently,
Valentina Zecca +3 more
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Inverse Design of Mirror‐Symmetric Disordered Systems for Broadband Perfect Transmission
Laser &Photonics Reviews, EarlyView.This work introduces an inverse design approach to achieve broadband perfect wave transmission in mirror‐symmetric disordered media. Leveraging symmetry simplifies optimization and enables control of multiple reflectionless states. Experiments in microwave waveguides confirm the design of exceptional points, bandpass filters, and broadband quasi ...
Zhazira Zhumabay +4 more
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