P-adic analysis (p-adic analysis) is a branch of mathematics that deals with the mathematical analysis of functions of p-adic numbers.

The theory of complex-valued numerical functions on the p-adic numbers is just part of the theory of locally compact groups. The usual meaning taken for p-adic analysis is the theory of p-adic-valued functions on spaces of interest.

P-adic analysis is mainly applied in number theory, where it has a signficant role in diophantine geometry and diophantine approximation. Some applications have required the development of p-adic functional analysis and spectral theory. In many ways p-adic analysis is less subtle than classical analysis, since the ultrametric inequality means, for example, that convergence of infinite series of p-adic numbers is much simpler. Topological vector spaces over p-adic fields show distinctive features; for example aspects relating to convexity and the Hahn-Banach theorem are different.

Also see

• Mahler's theorem, which treats a p-adic analog of Taylor series.
• Hensel's lemma
• locally compact space
• real analysis