essential subgroup
11Systolic geometry — In mathematics, systolic geometry is the study of systolic invariants of manifolds and polyhedra, as initially conceived by Charles Loewner, and developed by Mikhail Gromov and others, in its arithmetic, ergodic, and topological manifestations.… …
12taxonomy — taxonomic /tak seuh nom ik/, taxonomical, adj. taxonomically, adv. taxonomist, taxonomer, n. /tak son euh mee/, n. 1. the science or technique of classification. 2. Biol. the science dealing with the description, identification, naming, and… …
13Space group — In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains. In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered… …
14Plantain — This article is about the fruit. For the small herb, see Plantago. Plantain Plantains being sold. Details Hybrid parentage …
15Orthogonal matrix — In linear algebra, an orthogonal matrix (less commonly called orthonormal matrix[1]), is a square matrix with real entries whose columns and rows are orthogonal unit vectors (i.e., orthonormal vectors). Equivalently, a matrix Q is orthogonal if… …
16Food microbiology — is the study of the microorganisms which inhabit, create or contaminate food. Of major importance is the study of microorganisms causing food spoilage.cite book | author = Fratamico PM and Bayles DO (editor). | title = Foodborne Pathogens:… …
17Ojibwe language — Anishinaabemowin, ᐊᓂᔑᓈᐯᒧᐎᓐ Pronunciation [anɪʃɪnaːpeːmowɪn] Spoken in …
18Differential geometry of surfaces — Carl Friedrich Gauss in 1828 In mathematics, the differential geometry of surfaces deals with smooth surfaces with various additional structures, most often, a Riemannian metric. Surfaces have been extensively studied from various perspectives:… …
19respiratory disease — ▪ human disease Introduction any of the diseases and disorders that affect human respiration (respiration, human). Diseases of the respiratory system may affect any of the structures and organs that have to do with breathing, including the… …
20Group action — This article is about the mathematical concept. For the sociology term, see group action (sociology). Given an equilateral triangle, the counterclockwise rotation by 120° around the center of the triangle acts on the set of vertices of the… …
