scholarly journals High-order quadratures for integral operators with singular kernels

1995 ◽  
Vol 60 (3) ◽  
pp. 367-378 ◽  
Author(s):  
Bradley K. Alpert
Keyword(s):  
Integral Operators ◽  
High Order ◽  
Singular Kernels

Some misinterpretations and lack of understanding in differential operators with no singular kernels

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 594-612 ◽  
Author(s):  
Abdon Atangana ◽  
Emile Franc Doungmo Goufo
Keyword(s):  
Fractional Calculus ◽  
Power Law ◽  
Initial Value Problems ◽  
Differential Operators ◽  
Integral Operators ◽  
Initial Value ◽  
Complex Processes ◽  
Singular Kernels ◽  
Fractional Differential ◽  
Theoretical Results

AbstractHumans are part of nature, and as nature existed before mankind, mathematics was created by humans with the main aim to analyze, understand and predict behaviors observed in nature. However, besides this aspect, mathematicians have introduced some laws helping them to obtain some theoretical results that may not have physical meaning or even a representation in nature. This is also the case in the field of fractional calculus in which the main aim was to capture more complex processes observed in nature. Some laws were imposed and some operators were misused, such as, for example, the Riemann–Liouville and Caputo derivatives that are power-law-based derivatives and have been used to model problems with no power law process. To solve this problem, new differential operators depicting different processes were introduced. This article aims to clarify some misunderstandings about the use of fractional differential and integral operators with non-singular kernels. Additionally, we suggest some numerical discretizations for the new differential operators to be used when dealing with initial value problems. Applications of some nature processes are provided.

INTEGRAL REPRESENTATION OF QUANTUM MARTINGALES

2005 ◽  
Vol 08 (01) ◽  
pp. 55-72 ◽  
Author(s):  
UN CIG JI ◽  
KALYAN B. SINHA
Keyword(s):  
Integral Representation ◽  
Wide Class ◽  
Stochastic Integral ◽  
Integral Kernel ◽  
Integral Operators ◽  
Second Quantization ◽  
Kernel Operator ◽  
Stochastic Integral Representation ◽  
Singular Kernels

A stochastic integral representation in terms of generalized integral kernel operator is proved for a wide class of quantum martingales which includes regular martingales and the martingales determined by the second quantization of integral operators containing singular kernels.

The application of integral equation methods to the numerical solution of some exterior boundary-value problems

1971 ◽  
Vol 323 (1553) ◽  
pp. 201-210 ◽  
Keyword(s):  
Integral Equation ◽  
Wave Equation ◽  
Numerical Solution ◽  
Boundary Value Problems ◽  
Boundary Value ◽  
Integral Operators ◽  
Exterior Boundary ◽  
Integral Equation Methods ◽  
Singular Kernels ◽  
Single Integral

The application of integral equation methods to exterior boundary-value problems for Laplace’s equation and for the Helmholtz (or reduced wave) equation is discussed. In the latter case the straightforward formulation in terms of a single integral equation may give rise to difficulties of non-uniqueness; it is shown that uniqueness can be restored by deriving a second integral equation and suitably combining it with the first. Finally, an outline is given of methods for transforming the integral operators with strongly singular kernels which occur in the second equation.

scholarly journals Rough singular integrals on product spaces

2004 ◽  
Vol 2004 (67) ◽  
pp. 3671-3684 ◽  
Author(s):  
Ahmad Al-Salman ◽  
Hussain Al-Qassem
Keyword(s):  
Finite Type ◽  
Singular Integral ◽  
Singular Integrals ◽  
Integral Operators ◽  
Singular Integral Operators ◽  
Product Spaces ◽  
Lebesgue Spaces ◽  
Block Spaces ◽  
Singular Kernels

We study the mapping properties of singular integral operators defined by mappings of finite type. We prove that such singular integral operators are bounded on the Lebesgue spaces under the condition that the singular kernels are allowed to be in certain block spaces.

Certain Operators with Rough Singular Kernels

2003 ◽  
Vol 55 (3) ◽  
pp. 504-532 ◽  
Author(s):  
Jiecheng Chen ◽  
Dashan Fan ◽  
Yiming Ying
Keyword(s):  
Hardy Space ◽  
Sobolev Space ◽  
Singular Integral ◽  
Hardy Spaces ◽  
Integrable Function ◽  
Bounded Function ◽  
Bounded Operator ◽  
Integral Operators ◽  
Test Functions ◽  
Singular Kernels

AbstractWe study the singular integral operatordefined on all test functions f, where b is a bounded function, α ≥ 0, Ω (yʻ) is an integrable function on the unit sphere Sn-1 satisfying certain cancellation conditions. We prove that, for 1 < p < ∞, TΩ,α extends to a bounded operator from the Sobolev space to the Lebesgue space Lp with Ω being a distribution in the Hardy space Hq(Sn-1) where . The result extends some known results on the singular integral operators. As applications, we obtain the boundedness for TΩ,α on the Hardy spaces, as well as the boundedness for the truncated maximal operator .

scholarly journals Finitely-generated solutions of certain integral equations

1994 ◽  
Vol 37 (2) ◽  
pp. 325-345 ◽  
Author(s):  
D. Porter ◽  
D. S. G. Stirling
Keyword(s):  
Integral Equation ◽  
Finite Number ◽  
Recent Work ◽  
Integral Equations ◽  
Finite Rank ◽  
Integral Operators ◽  
Compact Operators ◽  
Particular Solutions ◽  
Singular Kernels ◽  
Special Case

Recent work has shown that the solutions of the second-kind integral equation arising from a difference kernel can be expressed in terms of two particular solutions of the equation. This paper establishes analogous results for a wider class of integral operators, which includes the special case of those arising from difference kernels, where the solution of the general case is generated by a finite number of particular cases. The generalisation is achieved by reducing the problem to one of finite rank. Certain non-compact operators, including those arising from Cauchy singular kernels, are amenable to this approach.

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