Results 81 to 90 of about 6,942 (263)

Stability Bounds for the Generalized Kadanoff‐Baym Ansatz in the Holstein Dimer

open access: yesContributions 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
wiley   +1 more source

Generalized Beth–Uhlenbeck Entropy Formula From the Φ‐Derivable Approach

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT We derive a generalized Beth–Uhlenbeck formula for the entropy of a dense fermion system with strong two‐particle correlations, including scattering states and bound states. We work within the Φ‐derivable approach to the thermodynamic potential.
David Blaschke, Gerd Röpke, Gordon Baym
wiley   +1 more source

Solutions of a Quadratic Inverse Eigenvalue Problem for Damped Gyroscopic Second-Order Systems

open access: yesJournal of Applied Mathematics, 2014
Given k pairs of complex numbers and vectors (closed under conjugation), we consider the inverse quadratic eigenvalue problem of constructing n×n real matrices M, D, G, and K, where M>0, K and D are symmetric, and G is skew-symmetric, so that the ...
Hong-Xiu Zhong   +2 more
doaj   +1 more source

Cross‐Entropy of Power Spectral Density Function: A Modal Identification Framework

open access: yesEarthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT The power spectral density (PSD) function of measured structural response contains a significant amount of information, including the modal parameters (natural frequencies, damping ratios). Output‐only system identification or modal identification technique can be used for extracting such modal parameters from the measured response or its ...
Su‐Hong Kim   +3 more
wiley   +1 more source

On Certain Translation Invariant Properties of Interior Transmission Spectra and Their Doppler’s Effect

open access: yesAdvances in Mathematical Physics, 2017
We study the translation invariant properties of the eigenvalues of scattering transmission problem. We examine the functional derivative of the eigenvalue density function Δ(x^) to the defining index of refraction n(x).
Lung-Hui Chen
doaj   +1 more source

Institutional Diversity in Banking and Economic Complexity

open access: yesInternational Journal of Finance &Economics, EarlyView.
ABSTRACT In this paper, we test whether institutional diversity in banking systems is beneficial to economic complexity, using data for Italian provinces in the period 1998–2017. We compute different indexes that consider diversity from an ownership, institutional, business model and competition point of view and find that higher diversity has a ...
Beniamino Pisicoli
wiley   +1 more source

Construction of 4 x 4 symmetric stochastic matrices with given spectra

open access: yesOpen Mathematics
The symmetric stochastic inverse eigenvalue problem (SSIEP) asks which lists of real numbers occur as the spectra of symmetric stochastic matrices. When the cardinality of a list is 4, Kaddoura and Mourad provided a sufficient condition for SSIEP by a ...
Jung Jaewon, Kim Donggyun
doaj   +1 more source

Artificial intelligence–driven decoupling structure–activity relationship for lithium‐ion batteries

open access: yesInfoScience, EarlyView.
Artificial intelligence can efferently accelerate the high‐throughput screening of battery materials, the analysis of multiphase mechanisms, and the precise prediction of capacity and cycle life. This review systematically summarizes the applications of machine learning (ML) in decoupling the complex structure‐activity relationships of lithium‐ion ...
Tao Wang   +6 more
wiley   +1 more source

Inverse Extremal Eigenvalue Problems for Multi-Arrowhead Pentadiagonal Matrices

open access: yesMathematics
We address the inverse extremal eigenvalue problem (IEEP) for multi-arrowhead pentadiagonal matrices, a structured class that combines pentadiagonal bandwidth with an alternating arrowhead structure.
Susana Arela-Pérez   +3 more
doaj   +1 more source

The inverse eigenvalue problem for Leslie matrices

open access: yesThe Electronic Journal of Linear Algebra, 2019
The Nonnegative Inverse Eigenvalue Problem (NIEP) is the problem of determining necessary and sufficient conditions for a list of $n$ complex numbers to be the spectrum of an entry--wise nonnegative matrix of dimension $n$. This is a very difficult and long standing problem and has been solved only for $n\leq 4$.
openaire   +4 more sources

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