Cauchy principal value

E239294

The Cauchy principal value is a method in mathematical analysis for assigning finite values to certain improper or divergent integrals and series by symmetrically balancing their singularities.

All labels observed (2)

Label Occurrences
Cauchy principal value canonical 2
Hadamard finite part 1

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Statements (46)

Predicate Object
instanceOf mathematical concept
method in mathematical analysis
abbreviation PV
p.v.
appliesTo divergent integrals
divergent series
improper integrals
singular integrals
characteristic balances singularities symmetrically
can assign finite value to divergent expressions
depends on the way limits are taken
is not absolutely convergent in general
uses symmetric limiting process
context appears in solving singular Cauchy-type integral equations
often denoted by a dash through the integral sign
used in defining boundary values of analytic functions
used to interpret integrals with poles on the path of integration
definitionExample PV ∫_{-a}^{a} f(x) dx = lim_{ε→0+} (∫_{-a}^{-ε} f(x) dx + ∫_{ε}^{a} f(x) dx)
PV ∫_{-∞}^{∞} f(x) dx = lim_{R→∞} ∫_{-R}^{R} f(x) dx
PV ∫_{a}^{b} f(x) dx with singularity at c is lim_{ε→0+} (∫_{a}^{c-ε} f(x) dx + ∫_{c+ε}^{b} f(x) dx)
example PV ∫_{-1}^{1} (1/x) dx = 0
field complex analysis
distribution theory
mathematical analysis
real analysis
namedAfter Augustin-Louis Cauchy
property coincides with usual integral when the integral converges absolutely
is invariant under odd symmetry for integrals over symmetric intervals
is linear where defined
may exist when the usual improper integral does not exist
relatedConcept Cauchy principal value self-linksurface differs
surface form: Hadamard finite part

Hilbert transform
conditional convergence
distribution (generalized function)
improper integral
principal value distribution of 1/x
usedIn Fourier analysis
Hilbert transform
Kramers–Kronig relations
complex contour integration
dispersion relations
distribution theory of tempered distributions
principal value integrals in physics
quantum field theory regularization techniques
regularization of divergent integrals
singular integral equations

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Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Augustin-Louis Cauchy knownFor Cauchy principal value
Augustin-Louis notableFor Cauchy principal value
subject surface form: Augustin-Louis Cauchy
Cauchy principal value relatedConcept Cauchy principal value self-linksurface differs
this entity surface form: Hadamard finite part