(2,3,7) triangle group

E262443

The (2,3,7) triangle group is a Fuchsian group generated by reflections in the sides of a hyperbolic triangle with angles π/2, π/3, and π/7, notable for its connection to highly symmetric structures such as the Klein quartic.

All labels observed (3)

How this entity was disambiguated

Statements (41)

Predicate Object
instanceOf Fuchsian group
discrete subgroup of PSL(2,R)
triangle group
actsOn hyperbolic plane
hasAreaOfFundamentalTriangle π(1 - 1/2 - 1/3 - 1/7)
hasCategory Riemann surface theory
geometric group theory
hyperbolic geometry
hasCoxeterDiagram triangle with edge labels 2,3,7
hasCoxeterPresentation ⟨ r1,r2,r3 | r1² = r2² = r3² = (r1r2)² = (r2r3)³ = (r1r3)⁷ = 1 ⟩
hasFundamentalDomain hyperbolic triangle with angles π/2, π/3, π/7
hasGeneratorsOfOrder 2
3
7
hasIndexInOrientationPreservingSubgroup 2
hasMinimalSumOfReciprocals among hyperbolic triangle groups
hasOrbifoldNotation *237
hasOrientationPreservingOrbifoldNotation 237
hasOrientationPreservingQuotient PSL(2,7)
automorphism group of the Klein quartic
hasOrientationPreservingSubgroup (2,3,7) triangle group self-linksurface differs
surface form: (2,3,7) von Dyck group
hasPresentation ⟨ x,y,z | x² = y³ = z⁷ = xyz = 1 ⟩ (orientation-preserving subgroup)
hasQuotientOrbifold sphere with cone points of orders 2, 3, and 7
hasSignature (2,3,7)
hasTriangleAngle π/2
π/3
π/7
hasType cofinite Fuchsian group
isArithmetic true
isAssociatedWith Hurwitz surfaces
isCoxeterGroup true
isGeneratedBy reflections in the sides of a hyperbolic triangle
isHyperbolicTriangleGroup true
isMaximalHyperbolicTriangleGroup true
isNamedAfter its triangle angle orders 2, 3, and 7
isRelatedTo Hurwitz bound 84(g−1)
Klein quartic
isUsedIn construction of highly symmetric Riemann surfaces
theory of Hurwitz groups
satisfies 1/2 + 1/3 + 1/7 < 1
uniformizes Klein quartic

How these facts were elicited

Referenced by (3)

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

Klein quartic relatedToTriangleGroup (2,3,7) triangle group
Hurwitz bound on automorphism groups of curves relatedConcept (2,3,7) triangle group
this entity surface form: triangle group (2,3,7)
(2,3,7) triangle group hasOrientationPreservingSubgroup (2,3,7) triangle group self-linksurface differs
this entity surface form: (2,3,7) von Dyck group