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Locally profinite group

In mathematics, a locally profinite group is a Hausdorff topological group in which every neighborhood of the identity element contains a compact open subgroup.

Version
v1 · 2026-09-28 · History
Domain-specific #
10464
Domain group
Formal Sciences
Origin domain
Mathematics
Subdomains
Topological Groups, Representation Theory → Mathematics

Core Idea

Locally profinite group is treated here as the recurring mathematicslogicstatistics identity summarized by this source-grounded definition: In mathematics, a locally profinite group is a Hausdorff topological group in which every neighborhood of the identity element contains a compact open subgroup. In mathematics, a locally profinite group is a Hausdorff topological group in which every neighborhood of the identity element contains a compact open subgroup. Equivalently, a locally profinite group is a topological group that is Hausdorff, locally compact, and totally disconnected.

Scope of Application

  • Hecke algebra of a locally profinite group. Let C^\inftyc(G) denote the space of locally constant functions on G with compact support.

  • Examples. More generally, the matrix ring \operatorname{M}n(F) and the general linear group \operatorname{GL}n(F) are locally profinite.

  • Examples. Another example of a locally profinite group is the absolute Weil group of a non-archimedean local field: this is in contrast to the fact that the absolute Galois group of such.

  • Representations of a locally profinite group. Then a group homomorphism \psi: G \to \mathbb{C}^\times is continuous if and only if it has open kernel.

  • Representations of a locally profinite group. We now make a blanket assumption that G/K is at most countable for all open compact subgroups K.

Clarity

A clear use of Locally profinite group names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is In mathematics, a locally profinite group is a Hausdorff topological group in which every neighborhood of the identity element contains a compact open subgroup.

Manages Complexity

Locally profinite group compresses multiple mathematicslogicstatistics details into a stable diagnostic relation. The source shows both the central mechanism—thus, we set \widetilde{V} = \bigcupK (V)K where K is acting through \rho^ and set \widetilde{\rho} = \rho^ .—and the practical consequence—then a group homomorphism \psi: G \to \mathbb{C}^\times is continuous if and only if it has open kernel.

Abstract Reasoning

  1. Type the carrier. Identify the mathematicslogicstatistics entities to which the claim applies.
  2. State the relation. Use the source-grounded identity: In mathematics, a locally profinite group is a Hausdorff topological group in which every neighborhood of the identity element contains a compact open subgroup.
  3. Check operation and conditions. It is called the Hecke algebra of G and is denoted by \mathfrak{H}(G).
  4. Demand recognition evidence.

Knowledge Transfer

Within the home domain. Knowledge about Locally profinite group transfers literally when a new case preserves the same carrier type, relation, and recognition test. Let C^\inftyc(G) denote the space of locally constant functions on G with compact support. More generally, the matrix ring \operatorname{M}n(F) and the general linear group \operatorname{GL}n(F) are locally profinite. Beyond the home domain. No canonical parent is asserted for Locally profinite group.

Relationships to Other Abstractions

Local relationship map for Locally profinite groupParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Locallyprofinite groupDOMAINPrime abstraction: Group — is a kind ofGroupPRIME

Current abstraction Locally profinite group Domain-specific

Parents (1) — more general patterns this builds on

  • Locally profinite group is a kind of Group Prime

    A locally profinite group is a group with a Hausdorff topology and a basis of compact open subgroups.

Hierarchy paths (5) — routes to 5 parentless roots

Neighborhood in Abstraction Space

Locally profinite group sits in a crowded region of the domain-specific corpus (35th percentile for distinctiveness): several abstractions share nearly its structure, so a description that fits it tends to fit its neighbors too.

Family — Algebraic Structures, Groups & Operators (42 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08