enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Retraction (topology) - Wikipedia

    en.wikipedia.org/wiki/Retraction_(topology)

    A space is an absolute neighborhood retract for the class , written ⁡ (), if is in and whenever is a closed subset of a space in , is a neighborhood retract of . Various classes C {\displaystyle {\mathcal {C}}} such as normal spaces have been considered in this definition, but the class M {\displaystyle {\mathcal {M}}} of metrizable spaces ...

  3. Section (category theory) - Wikipedia

    en.wikipedia.org/wiki/Section_(category_theory)

    The concept in topology was defined by Karol Borsuk in 1931. [ 2 ] Borsuk's student, Samuel Eilenberg , was with Saunders Mac Lane the founder of category theory, and (as the earliest publications on category theory concerned various topological spaces) one might have expected this term to have initially be used.

  4. Karol Borsuk - Wikipedia

    en.wikipedia.org/wiki/Karol_Borsuk

    Karol Borsuk (8 May 1905 – 24 January 1982) was a Polish mathematician. His main area of interest was topology . He made significant contributions to shape theory , a term which he coined.

  5. Pattern recognition (psychology) - Wikipedia

    en.wikipedia.org/wiki/Pattern_recognition...

    In psychology and cognitive neuroscience, pattern recognition is a cognitive process that matches information from a stimulus with information retrieved from memory. [1]Pattern recognition occurs when information from the environment is received and entered into short-term memory, causing automatic activation of a specific content of long-term memory.

  6. Bing–Borsuk conjecture - Wikipedia

    en.wikipedia.org/wiki/Bing–Borsuk_conjecture

    In mathematics, the Bing–Borsuk conjecture states that every -dimensional homogeneous absolute neighborhood retract space is a topological manifold. The conjecture has been proved for dimensions 1 and 2, and it is known that the 3-dimensional version of the conjecture implies the Poincaré conjecture .

  7. Retract (group theory) - Wikipedia

    en.wikipedia.org/wiki/Retract_(group_theory)

    The following is known about retracts: A subgroup is a retract if and only if it has a normal complement. [4] The normal complement, specifically, is the kernel of the retraction. Every direct factor is a retract. [1] Conversely, any retract which is a normal subgroup is a direct factor. [5] Every retract has the congruence extension property.

  8. Samuel Eilenberg - Wikipedia

    en.wikipedia.org/wiki/Samuel_Eilenberg

    He worked on the axiomatic treatment of homology theory with Norman Steenrod (and the Eilenberg–Steenrod axioms are named for the pair), and on homological algebra with Saunders Mac Lane. In the process, Eilenberg and Mac Lane created category theory. Eilenberg was a member of Bourbaki and, with Henri Cartan, wrote the 1956 book Homological ...

  9. Nerve complex - Wikipedia

    en.wikipedia.org/wiki/Nerve_complex

    Constructing the nerve of an open good cover containing 3 sets in the plane.. In topology, the nerve complex of a set family is an abstract complex that records the pattern of intersections between the sets in the family.