homology
Language: English
Part of speech: noun
Forms: form: homologies
Etymology: From Latin homologia, from Ancient Greek ὁμολογία (homología, “agreement, assent”); compare French homologie. By surface analysis, homo- + -logy.
In topology, first used by French polymath Henri Poincaré, in the sense (close to what is now called a bordism) of a relation between manifolds mapped into a reference manifold: that is, the property of such manifolds that they form the boundary of a higher-dimensional manifold inside the reference manifold. Poincaré's version was eventually replaced by the more general singular homology, which is what mathematicians now mean by homology.
Senses: examples: 1863, George Salmon, A Treatise on Conic Sections, Longman, Brown, Green, Longman, and Roberts, 4th Edition, page 61,
Two triangles are said to be homologous, when the intersections of the corresponding sides lie on the same right line called the axis of homology: prove that the lines joining the corresponding vertices meet in a point [called the centre of homology].
1885, Charles Leudesdorf (translator), Luigi Cremona, Elements of Projective Geometry, Oxford University Press (Clarendon Press), page 11,
Two corresponding straight lines therefore always intersect on a fixed straight line, which we may call s; thus the given figures are in homology, O being the centre, and s the axis, of homology.
topics: geometry
mathematics
sciences
glosses: The relationship of being homologous; a homologous relationship.
specifically, such relationship in the context of the geometry of perspective.
qualifier: projective geometry
examples: text: If the homology centre lies on the homology axis, the homology is said to be singular or parabolic; otherwise, it is called non-singular or hyperbolic.
topics: geometry
mathematics
sciences
glosses: The relationship of being homologous; a homologous relationship.
An automorphism of the projective plane (representing a perspective projection) that leaves all the points of some straight line (the homology axis) fixed and maps all the lines through some single point (the homology centre) onto themselves.
qualifier: projective geometry
examples: text: One encounters a similar situation in homology theory. Beside singular homology, which is a homotopy invariant, and Čech homology, which is a shape invariant, there exists strong homology, which is a strong shape invariant. In the special case of metric compacta, this homology was introduced by N.E. Steenrod in 1940 and is often referred to as the Steenrod homology.
ref: 2000, Sibe Mardešić, Strong Shape and Homology, Springer, page v:
text: Brieskorn homology spheres are a special case of Siefert fibered homology spheres.
ref: 2002, Nikolai Saveliev, Invariants of Homology 3-Spheres, Springer, page 2:
topics: algebraic-topology
mathematics
sciences
topology
glosses: The relationship of being homologous; a homologous relationship.
A general way of associating a sequence of algebraic objects, such as abelian groups or modules, to a sequence of topological spaces; also used attributively: see Usage notes below.
examples: text: Because of their connection with both homology and cohomology, chain complexes are an important topic of study in homological algebra.
topics: algebra
mathematics
sciences
glosses: The relationship of being homologous; a homologous relationship.
Given a chain complex {Gₙ} and its associated set of homomorphisms {Hₙ}, the rule which explains how each Hₙ maps Gₙ into the kernel of Gₙ₊₁.
topics: chemistry
natural-sciences
physical-sciences
glosses: The relationship of being homologous; a homologous relationship.
The relationship, between elements, of being in the same group of the periodic table.
topics: chemistry
natural-sciences
organic-chemistry
physical-sciences
glosses: The relationship of being homologous; a homologous relationship.
The relationship, between organic compounds, of being in the same homologous series.
examples: 2000, Julie A. Hawkins, Chapter 2: A survey of primary homology assessment, Robert Scotland, R. Toby Pennington (editors), Homology and Systematics, Taylor & Francis, The Systematics Association, page 22,
The objective of this study is to classify approaches to primary homology assessment, and to quantify the extent to which different approaches are found in the literature by examining variation in the ways characters are defined and coded in a data matrix.
topics: biology
human-sciences
natural-sciences
psychology
sciences
glosses: The relationship of being homologous; a homologous relationship.
The relationship, between characteristics or behaviours, of having a shared evolutionary or developmental origin;
coordinate_terms: homomorphism
topics: biology
human-sciences
natural-sciences
psychology
sciences
glosses: The relationship of being homologous; a homologous relationship.
The relationship, between characteristics or behaviours, of having a shared evolutionary or developmental origin;
(evolutionary theory) specifically, a correspondence between structures in separate life forms having a common evolutionary origin, such as that between mammalian flippers and hands.
specifically, a correspondence between structures in separate life forms having a common evolutionary origin, such as that between mammalian flippers and hands.
coordinate_terms: homomorphism
qualifier: evolutionary theory
topics: biology
genetics
medicine
natural-sciences
sciences
glosses: The relationship of being homologous; a homologous relationship.
The presence of the same series of bases in different but related genes.
topics: anthropology
human-sciences
sciences
glosses: The relationship of being homologous; a homologous relationship.
The relationship, between temporally separated human beliefs, practices or artefacts, of possessing shared characteristics attributed to genetic or historical links to a common ancestor.
Derived terms: axis of homology
center of homology
centre of homology
cohomology
Floer homology
homology axis
homology center
homology centre
homology group
homology modeling
homology modelling
homology sphere
hyperbolic homology
hyperhomology
Khovanov homology
microhomology
nonhomology
parabolic homology
semihomology
sequence homology
singular homology
Related terms: analogy
homolog
homologue
homologation
homological
homologism
paromologia
homothety
homotopy