Results 21 to 30 of about 128 (120)

Center conditions for a cubic differential system with one invariant straight line and one invariant conic

Acta et Commentationes: Ştiinţe Exacte şi ale Naturii
In this work we find the center conditions for a cubic system of differential equations with a critical point of a center or a focus type having one invariant straight line and one invariant conic. The center-focus problem is studied by using the Darboux
Dumitru Cozma
doaj   +1 more source

Unified Ray and Amplitude Tracing ODE Systems for the Eikonal and Transport Equations via Contact Geometry

Studies in Applied Mathematics, Volume 157, Issue 3, September 2026.
ABSTRACT High‐frequency seismic wave descriptions are essential for fundamental geophysical applications, including earthquake hypocenter location, magnitude estimation, and traveltime–amplitude tomography. These descriptions rely on two coupled PDEs: the eikonal equation (governing traveltimes) and the transport equation (governing amplitudes ...
Ahmet Beyaz, Çağrı Diner, Mustafa Tevfik Aktar   +2 more
wiley   +1 more source

Darboux Integrability Of the Biological System

Al-Rafidain Journal of Computer Sciences and Mathematics
In the given paper, we investigate the integrability of a mathematical model of a 3D biological system. Our results show that the system admits a polynomial first integrals for some parameters, an invariant algebraic surface with an exponential factor ...
Zakariya Hashem Ali, Ahmad Muhamad Husien   +1 more
doaj   +1 more source

Isometric immersions into three‐dimensional unimodular metric Lie groups

Journal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract We study isometric immersions of surfaces into simply connected three‐dimensional unimodular Lie groups endowed with either Riemannian or Lorentzian left‐invariant metrics, assuming that Milnor's operator is diagonalizable in the Lorentzian case.
Ildefonso Castro, José M. Manzano, José S. Santiago   +2 more
wiley   +1 more source

Overland Flow Dynamics on a Cracked Soil Slope Under Drying‐Wetting Cycles: An Integrated Hydrological and Infrared Thermographic Study

Water Resources Research, Volume 62, Issue 8, August 2026.
Abstract Although overland flow strongly governs soil erosion and sediment transport, its response to desiccation cracking induced by drying‐wetting cycles is not fully understood. This study addresses this gap through laboratory rainfall simulations on a slope model subjected to three drying‐wetting cycles.
Ting‐Ting Chen, Qing Cheng, Qi Zhang, Chao‐Sheng Tang, Yang Lu, Bin Shi   +5 more
wiley   +1 more source

Weinstein neighborhood theorems for stratified subspaces

Journal of the London Mathematical Society, Volume 114, Issue 2, August 2026.
Abstract By analogy with Weinstein's neighborhood theorem, we prove a uniqueness result for symplectic neighborhoods of a large family of stratified subspaces. This result generalizes existing constructions, for example, in the search for exotic Lagrangians.
Yael Karshon, Sara B. Tukachinsky, Yoav Zimhony   +2 more
wiley   +1 more source

An Algebraic Study of Parametric Stokes Phenomena

Studies in Applied Mathematics, Volume 157, Issue 1, July 2026.
ABSTRACT We investigate geometric aspects of co‐equational parametric resurgence, by studying physical problems whose formal asymptotic solutions give rise to Borel transforms lying on an algebraic curve. This perspective allows us to elucidate concepts unique to parametric resurgence such as singularity structures, (virtual) turning points, and the ...
Inês Aniceto, Samuel Crew
wiley   +1 more source

Affine hypersurfaces and superintegrable systems

Journal of the London Mathematical Society, Volume 114, Issue 1, July 2026.
Abstract It was recently shown that under mild assumptions, second‐order conformally superintegrable systems can be encoded in a (0,3)‐tensor, called structure tensor. For abundant systems, this approach led to algebraic integrability conditions that essentially allow one to restore a system from the knowledge of its structure tensor in a point on the ...
Vicente Cortés, Andreas Vollmer
wiley   +1 more source

Exact Solution of the Nonlocal $\mathcal{PT}$-Symmetric (2 + 1)-Dimensional Hirota–Maxwell–Bloch System

Mathematics
This paper investigates the (2 + 1)-dimensional nonlocal Hirota–Maxwell–Bloch (NH-MB) system under various types of nonlocality. The mathematical consistency of possible nonlocal structures is analyzed, and three types that lead to a well-posed system ...
Zhaidary Myrzakulova, Zaruyet Zakariyeva, Anar Zhumakhanova, Kuralay Yesmakhanova   +3 more
doaj   +1 more source

3D definition of the river bankfull stage from topographic LiDAR

Earth Surface Processes and Landforms, Volume 51, Issue 6, June 2026.
A 3D definition of river bankfull stage based on hydraulic depth derived from high‐density topographic LiDAR is proposed and implemented through the Bf3D framework, applied at the reach scale across 28 French rivers. Extending analysis beyond individual cross‐sections opens new opportunities for large‐scale, automated hydromorphological monitoring ...
Alexandre Retat, Nathalie Thommeret, Frédéric Gob, Jean‐Stéphane Bailly, Laurent Lespez, Thomas Depret, Karl Kreutzenberger   +6 more
wiley   +1 more source