Distribution derivatives and jump sources
Research context
research method · established · As of 2026-10-10
Distribution derivatives transfer differentiation to a test function with the integration-by-parts sign.
Key knowledge
Distribution derivatives transfer differentiation to a test function with the integration-by-parts sign. Every distribution has derivatives of all orders in this sense. On R, the Heaviside step has derivative delta-zero and |x| has second derivative 2 delta-zero. These identities represent jumps and point sources, without treating delta as a finite-valued density.
Values and equations
<D-alpha T,phi>=(-1)^|alpha| <T,D-alpha phi>; H'=delta_0
- T
- Distribution
- alpha
- Derivative multi-index
- phi
- Test function
- H
- Heaviside step function
Conditions and scope
- Test functions have compact support so boundary terms vanish.
- A weak derivative in L-p is a stronger condition than the existence of a derivative as a distribution.
Sources · 1
References
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Evidence and review
Author checked this English statement, displayed equation where present and stated hypotheses against these source locations: §§1.2, 2.1–2.2, 3.1, 11.1–11.2, 12.1–12.2, 13.1, 15.1–15.3, 17.1–17.3; each record narrows its applicable claim. The check is bounded to the recorded claims; no complete proof reconstruction, software proof replay or universal literature completeness is claimed.
2026-10-10 · Author source-body/statement/equation/domain check, with graph associations scoped individually. Separate independent content/source/inventory review is required before branch closure.
Entry details
Permanent link to this entry ↗- Record identity
- research-math-distribution-derivative
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference