Results 31 to 40 of about 297,006 (207)

Data‐driven emulation of flow‐dependent background‐error variance in variational data assimilation

Quarterly Journal of the Royal Meteorological Society, EarlyView.
A machine‐learning approach is developed to emulate flow‐dependent background‐error variance within a variational data assimilation framework. The method reproduces uncertainty information that would normally require a 50‐member ensemble using only five members, while maintaining comparable observation fit and forecast performance.
Wei Pan, Massimo Bonavita, Marcin Chrust, Elías Hólm   +3 more
wiley   +1 more source

Fixed point theory in RWC–Banach algebras

Nonlinear Analysis
In this paper, we prove some fixed point results for the sum and the product of nonlinear continuous operators acting on an RWC–Banach algebra. Our result is formulated in terms of topological conditions on the operators.
Józef Banaś, Bilel Krichen, Bilel Mefteh, Donal O’Regan   +3 more
doaj   +1 more source

Algebraic ideals of semiprime Banach algebras [PDF]

Glasgow Mathematical Journal, 1991
AbstractIf A is a semiprime Banach algebra, soc A, rad A the socle and radical of A, then Soc A ∩ rad A = (0). This elementary result enables us to prove some results concerning algebraic ideal and algebraic elements modulo the socle of A. We also deduce several conditions for A equivalent to the condition dim A <+∞.
GIOTOPOULOS, S, ROUMELIOTIS, M
openaire   +2 more sources

Spectral Submanifolds of Delay Systems: Control in Continuous and Discrete Time

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This paper presents both continuous‐time and discretization‐based approaches for constructing spectral submanifolds (SSMs) for time delay systems. The continuous‐time approach built upon sun–star calculus, reformulates the governing delay differential equation (DDE) as an operator differential equation (OpDE).
Bence Szaksz, Gábor Orosz, Gábor Stépán   +2 more
wiley   +1 more source

Supersets for the spectrum of elements in extended Banach algebras

International Journal of Mathematics and Mathematical Sciences, 1989
If A is a Banach Algebra with or without an identity, A can be always extended to a Banach algebra A¯ with identity, where A¯ is simply the direct sum of A and C, the algebra of complex numbers. In this note we find supersets for the spectrum of elements
Morteza Seddighin
doaj   +1 more source

F-cone metric spaces over Banach algebra

Fixed Point Theory and Applications, 2017
The paper deals with the achievement of introducing the notion of F-cone metric spaces over Banach algebra as a generalization of N p $N_{p}$ -cone metric space over Banach algebra and N b $N_{b}$ -cone metric space over Banach algebra and studying some ...
Jerolina Fernandez, Neeraj Malviya, Stojan Radenovič, Kalpana Saxena   +3 more
doaj   +1 more source

Quotients of Local Banach Algebras are Local Banach Algebras

Publications of the Research Institute for Mathematical Sciences, 1991
We show that quotients of local Banach algebras are local Banach algebras. This solves a problem posed by B. Blackadar in his book on K -Theory [BLA1]. Furthermore our techniques allow to prove additional density Theorems for the K -Theory of normed ...
openaire   +2 more sources

Risk Measure Duality Without Structure

Mathematical Finance, EarlyView.
ABSTRACT We study risk measures on vector spaces of random variables which a priori have little structure, such as spaces lacking law invariance or a lattice structure. Ensuring the existence of a tractable dual representation (one which does not contain non‐sigma‐additive measures) is one of the main problems in risk measure theory, and we address it ...
Vasily Melnikov
wiley   +1 more source

On the Homology Theory of Operator Algebras

International Journal of Mathematics and Mathematical Sciences, 2012
We investigate the cyclic homology and free resolution effect of a commutative unital Banach algebra. Using the free resolution operator, we define the relative cyclic homology of commutative Banach algebras. Lemmas and theorems of this investigation are
Alaa Hassan Noreldeen
doaj   +1 more source

Fragmentation–Coagulation Processes With Advection or Diffusion in Space

Mathematical Methods in the Applied Sciences, Volume 49, Issue 17, Page 17952-17982, 30 November 2026.
ABSTRACT In this paper, we consider a continuous fragmentation–coagulation model in which the reacting particles can be transported in physical space through either advection or diffusion. We prove new results on the generation of C0‐semigroups with parameter and use them to show that the abstract Cauchy problem associated with a more general version ...
Jacek Banasiak, Nduduzo Majozi
wiley   +1 more source