Now showing items 61-80 of 713

    Sampling recovery of functions with mixed smoothness 

    Kosov, Egor; Temlyakov, V. N. (Publication date: 2025-04-12)

    Recently, a substantial progress in studying the problem of optimal sampling recovery was made in a number of papers. In particular, this resulted in some progress in studying sampling recovery on function classes with ...

    Thumbnail

    A note on the local behavior of the Taylor method for stiff ODEs 

    Forrier, P. P.; Gimeno, J.; Jorba, Angel (Publication date: 2025-07-01)

    In this note we study the behavior of the coefficients of the Taylor method when computing the numerical solution of stiff Ordinary Differential Equations. First, we derive an asymptotic formula for the growth of the ...

    Thumbnail

    Modelling large mass removal in adsorption columns 

    Myers, T. G.; Calvo-Schwarzwalder, M.; Font, F.; Valverde, A. (Publication date: 2025-04-01)

    A novel mathematical model is developed to describe column adsorption when the contaminant constitutes a significant amount of the fluid. This requires tracking the variation of pressure and velocity, in addition to the ...

    Thumbnail

    Towards a Fluid Computer 

    Cardona, R.; Miranda, E.; Peralta-Salas, D. (Publication date: 2025-03-13)

    In 1991, Moore (Nonlinearity 4:199–230, 1991) raised a question about whether hydrodynamics is capable of performing computations. Similarly, in 2016, Tao (J Am Math Soc 29(3):601–674, 2016) asked whether a mechanical ...

    Thumbnail

    Separating the Edges of a Graph by Cycles and by Subdivisions of K4 

    Botler, F.; Naia, Tássio (Publication date: 2025-04-10)

    A separating system of a graph (Formula presented.) is a family (Formula presented.) of subgraphs of (Formula presented.) for which the following holds: for all distinct edges (Formula presented.) and (Formula presented.) ...

    Thumbnail

    A parametrization algorithm to compute lower dimensional elliptic tori in Hamiltonian systems 

    Caracciolo, C.; Figueras, J. L.; Haro, A. (Publication date: 2025-01-10)

    We present an algorithm for the construction of lower dimensional elliptic tori in parametric Hamiltonian systems by means of the parametrization method with the tangent and normal frequencies being prescribed. This requires ...

    Thumbnail

    Lagrangian descriptors in geophysical flows: a survey 

    Curbelo, Jezabel (Publication date: 2025-03-16)

    This survey focuses on the application of Lagrangian descriptors to reveal the geometry of phase space structures that determine transport in dynamical systems. We present diverse formulations of the method and examine ...

    Thumbnail

    Carleson conditions for weights: The quantitative small constant case 

    Bortz, S.; Egert, M.; Saari, O. (Publication date: 2025-08-01)

    We investigate the small constant case of a characterization of A∞ weights due to Fefferman, Kenig and Pipher. In their work, Fefferman, Kenig and Pipher bound the logarithm of the A∞ constant by the Carleson norm of a ...

    Thumbnail

    Examples of optimal Hölder regularity in semilinear equations involving the fractional Laplacian 

    Csato, Gyula; Mas Blesa, Albert (Publication date: 2025-06-01)

    We discuss the Hölder regularity of solutions to the semilinear equation involving the fractional Laplacian (−Δ)su=f(u) in one dimension. We put in evidence a new regularity phenomenon which is a combined effect of the ...

    Thumbnail

    On the local geometry of the moduli space of (2,2)-threefolds in A9 

    Colombo, E.; Frediani, P.; Naranjo, Juan Carlos; Pirola, G. P. (Publication date: 2025-01-06)

    We study the local geometry of the moduli space of intermediate Jacobians of (2,2)-threefolds in P2× P2. More precisely, we prove that a composition of the second fundamental form of the Siegel metric in A9 restricted to ...

    Thumbnail

    Pebble trees 

    Pilaud, Vincent (Publication date: 2024-02-10)

    A pebble tree is an ordered tree where each node receives some colored pebbles, in such a way that each unary node receives at least one pebble, and each subtree has either one more or as many leaves as pebbles of each ...

    Thumbnail

    Limit cycles and critical periods with non-hyperbolic slow-fast systems 

    De Maesschalck, P.; Torregrosa, J. (Publication date: 2025-07-15)

    By considering planar slow-fast systems with a curve of double singular points, we obtain lower bounds on the number of limit cycles of polynomial systems surrounding a single singular point, as well as on the number of ...

    Thumbnail

    A Non-Parametric Estimation Method of the PopulationSize in Capture-Recapture Experiments With RightCensored Data 

    Blasco-Moreno, A.; Puig, P. (Publication date: 2025-04-02)

    We present a new non-parametric approach for estimating the total number of animals or species when we only have information on the number of animals or species that have been observed once, twice, (Formula presented.), ...

    Thumbnail

    Nondensity results in high-dimensional stable Hamiltonian topology 

    Cardona, Robert; Gironella, F. (Publication date: 2025-04-04)

    We push forward the study of higher dimensional stable Hamiltonian topology by establishing two nondensity results. First, we prove that stable hypersurfaces are not (Formula presented.) -dense in any isotopy class of ...

    Thumbnail

    On Darmon’s program for the generalized Fermat equation, I 

    Billerey, N.; Chen, I.; Dieulefait, L.; Freitas, N. (Publication date: 2025-03-25)

    In 2000, Darmon described a program to study the generalized Fermat equation using modularity of abelian varieties of GL 2-type over totally real fields. The original approach was based on hard open conjectures, which have ...

    Thumbnail

    Smooth imploding solutions for 3D compressible fluids 

    Buckmaster, T.; Cao-Labora, G.; Gómez-Serrano, J. (Publication date: 2025-02-12)

    Building upon the pioneering work of Merle, Raphaël, Rodnianski and Szeftel [67, 68, 69], we construct exact, smooth self-similar imploding solutions to the 3D isentropic compressible Euler equations for ideal gases for ...

    Thumbnail

    On the automorphism group of quotient modular curves 

    Bars, F.; Dalal, T. (Publication date: 2025-06-15)

    In this article, we determine the automorphism group of all the quotient modular curves of the modular curve X0(pq), where p,q are two distinct primes. In obtaining such results, we provide different insights to compute ...

    Thumbnail

    Oscillatory Motions, Parabolic Orbits and Collision Orbits in the Planar Circular Restricted Three-Body Problem 

    Lamas, J.; Guardia, M.; Sea, T. M. (Publication date: 2025-04-10)

    In this paper we consider the planar circular restricted three body problem (PCRTBP), which models the motion of a massless body under the attraction of other two bodies, the primaries, which describe circular orbits around ...

    Thumbnail

    Resource-consumer dynamics in drylands: Modeling the role of plant–plant facilitation–competition shifts with a piecewise system 

    da Cruz, L. P. C.; Torregrosa, J.; Berdugo, M.; Sardanyes, J. (Publication date: 2025-03-01)

    In drylands, water availability determines plant population densities and whether they cooperate via facilitation or compete. When water scarcity intensifies, plant densities decrease and competition for water surpasses ...

    Thumbnail

    Network Mechanisms Underlying the Regional Diversity of Variance and Time Scales of the Brain’s Spontaneous Activity Fluctuations 

    Ponce Álvarez, Adrián Fernando (Publication date: 2025-03-05)

    The brain’s activity fluctuations have different temporal scales across the brain regions, with associative regions displaying slower timescales than sensory areas. This hierarchy of timescales has been shown to correlate ...