In
mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
, the Bessel potential is a
potential (named after
Friedrich Wilhelm Bessel) similar to the
Riesz potential but with better decay properties at infinity.
If ''s'' is a complex number with positive real part then the Bessel potential of order ''s'' is the operator
:
where Δ is the
Laplace operator and the
fractional power is defined using Fourier transforms.
Yukawa potentials are particular cases of Bessel potentials for
in the 3-dimensional space.
Representation in Fourier space
The Bessel potential acts by multiplication on the
Fourier transforms: for each
:
Integral representations
When
, the Bessel potential on
can be represented by
:
where the Bessel kernel
is defined for
by the integral formula
:
Here
denotes the
Gamma function
In mathematics, the gamma function (represented by , the capital letter gamma from the Greek alphabet) is one commonly used extension of the factorial function to complex numbers. The gamma function is defined for all complex numbers excep ...
.
The Bessel kernel can also be represented for
by
:
This last expression can be more succinctly written in terms of a modified
Bessel function, for which the potential gets its name:
:
Asymptotics
At the origin, one has as
,
:
:
:
In particular, when
the Bessel potential behaves asymptotically as the
Riesz potential.
At infinity, one has, as
,
:
See also
*
Riesz potential
*
Fractional integration
*
Sobolev space
*
Fractional Schrödinger equation
A fraction is one or more equal parts of something.
Fraction may also refer to:
* Fraction (chemistry), a quantity of a substance collected by fractionation
* Fraction (floating point number), an (ambiguous) term sometimes used to specify a part ...
*
Yukawa potential
References
*
*
*
*
* {{citation , first=Elias , last=Stein , authorlink=Elias Stein , title=Singular integrals and differentiability properties of functions , publisher=
Princeton University Press
Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large.
The press was founded by Whitney Darrow, with the financial ...
, location=Princeton, NJ , year=1970 , isbn=0-691-08079-8 , url-access=registration , url=https://archive.org/details/singularintegral0000stei
Fractional calculus
Partial differential equations
Potential theory
Singular integrals