Results 111 to 120 of about 403 (256)

Robust Tests of Forecast Accuracy for Factor‐Augmented Regressions With an Application to the Novel EA‐MD‐QD Dataset

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
wiley   +1 more source

Integrable and Chaotic Systems Associated with Fractal Groups. [PDF]

Entropy (Basel), 2021
Grigorchuk R, Samarakoon S.
europepmc   +1 more source

Spatial Lock‐In and Reclamation Delay in Coal‐Subsidence Landscapes: Land Degradation Under Passive Water‐Retention Strategies

Land Degradation &Development, EarlyView.
ABSTRACT In coal‐grain composite regions, intensive underground coal extraction causes large‐scale surface subsidence; under shallow groundwater conditions, these subsided landscapes rapidly transform former croplands into persistent open water bodies, creating long‐term inundated landscapes. Passive water‐retention strategies in these areas often rely
Ruihao Cui, Lingtong Meng, Xiao Wang, Yan Han, Jiazheng Han, Jennifer Franklin, Zhenqi Hu   +6 more
wiley   +1 more source

Gelfand-Kirillov dimension in relatively free algebras [PDF]

, 2018
Orientador: Plamen Emilov KochloukovTese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação CientíficaResumo: Neste trabalho estudamos o invariante denominado dimensão de Gelfand-Kirillov para álgebras com ...
Machado, Gustavo Grings, 1987-
core  

Theory of Supercritical Coupling and Generalized Bound States in the Continuum

Laser &Photonics Reviews, EarlyView.
We develop a general theory of supercritical coupling and generalized bound states in the continuum (gBICs), revealing how interference between radiative and absorptive channels enables quality factors beyond conventional material‐loss limits. The framework unifies non‐Hermitian mode coupling, causality‐driven reactive interactions, and interference ...
Sergio Balestrieri, Bruno Miranda, Silvia Romano, Gianluigi Zito   +3 more
wiley   +1 more source

Generating Helical Polymorphic Beams Using Dielectric Metasurfaces

Laser &Photonics Reviews, EarlyView.
Helix‐shaped polymorphic beams are optical fields whose intensity maxima spiral around the propagation axis, enabling particle manipulation through attractive or repulsive forces. Traditionally requiring expensive spatial light modulators, metasurfaces now provide a compact, cost‐effective alternative. This work demonstrates general helical polymorphic
Maryam Setareh, Yang Xu, Jose A. Rodrigo, Kenneth B. Crozier   +3 more
wiley   +1 more source

The Hopf algebra of skew shapes, torsion sheaves on A^n/F_1, and ideals in Hall algebras of monoid representations [PDF]

, 2018
We study ideals in Hall algebras of monoid representations on pointed sets corresponding to certain conditions on the representations. These conditions include the property that the monoid act via partial permutations, that the representation possess a ...
Szczesny, Matt M.
core  

Kuga–Satake Construction on Families of K3 Surfaces of Picard Rank 14

Mathematische Nachrichten, EarlyView.
ABSTRACT The isometry between the type IV6 and the type II4 hermitian symmetric domains suggests a possible relation between suitable moduli spaces of K3 surfaces of Picard rank 14 and of polarized abelian 8‐folds with totally definite quaternion multiplication. We show how this isometry induces a geometrically meaningful map between such moduli spaces
Flora Poon
wiley   +1 more source

On Matrix‐Based Cryptography Using Matrix Norm and Special Integer Sequences

Mathematische Nachrichten, EarlyView.
ABSTRACT In this paper, a novel matrix‐based encryption approach based on the Affine Hill cipher is presented. The key matrix is constructed using the Narayana integer sequence, and the Frobenius norm of the key matrix is used as a scaling factor in the key construction.
Melih Göcen, Sümeyye Hacer Büyükakyol   +1 more
wiley   +1 more source

The Two Extremal Rays of Some Hyper–Kähler Fourfolds

Mathematische Nachrichten, EarlyView.
ABSTRACT We consider projective Hyper–Kähler manifolds of dimension 4 that are deformation equivalent to Hilbert squares of K3 surfaces. In case such a manifold admits a divisorial contraction, the exceptional divisor is a conic bundle over a K3 surface. A classification of lattice embeddings implies that there are five types of such conic bundles.
Federica Galluzzi, Bert van Geemen
wiley   +1 more source