Subgroup in the context of Embedding (mathematics)

The Volga Tatars or simply Tatars (Tatar: татарлар, romanized: tatarlar; Russian: татары, romanized: tatary) are a Turkic ethnic group native to the Volga-Ural region of western Russia, and contains multiple subgroups. Tatars are the second-largest ethnic group in Russia after ethnic Russians. They are primarily found in Tatarstan, where they make up 53.6% of the population. Their native language is Tatar, and are primarily followers of Sunni Islam.

"Tatar" as an ethnonym has a very long and complicated history, and in the past was often used as an umbrella term for different Turkic and Mongolic tribes. Nowadays it mostly refers exclusively to Volga Tatars (known simply as "Tatars"; Tatarlar), who became its "ultimate bearers" after the founding of Tatar ASSR (1920–1990; now Tatarstan). The ethnogenesis of Volga-Ural Tatars is still debated, but their history is usually connected to the Kipchak-Tatars of Golden Horde (1242–1502), and also to its predecessor, Volga Bulgaria (900s–1200s), whose adoption of Islam is celebrated yearly in Tatarstan. After the collapse of the Golden Horde, ancestors of modern Tatars formed the Khanate of Kazan (1438–1552), which lost its independence to Russia after the Siege of Kazan in 1552.

In mathematics, specifically in group theory, two groups are commensurable if they differ only by a finite amount, in a precise sense. The commensurator of a subgroup is another subgroup, related to the normalizer.

In group theory, the symmetry group of a geometric object is the group of all transformations under which the object is invariant, endowed with the group operation of composition. Such a transformation is an invertible mapping of the ambient space which takes the object to itself, and which preserves all the relevant structure of the object. A frequent notation for the symmetry group of an object X is G = Sym(X).

For an object in a metric space, its symmetries form a subgroup of the isometry group of the ambient space. This article mainly considers symmetry groups in Euclidean geometry, but the concept may also be studied for more general types of geometric structure.

In abstract algebra, a generating set of a group is a subset of the group set such that every element of the group can be expressed as a combination (under the group operation) of finitely many elements of the subset and their inverses.

In other words, if ${\displaystyle S}$ is a subset of a group ${\displaystyle G}$, then ${\displaystyle \langle S\rangle }$, the subgroup generated by ${\displaystyle S}$, is the smallest subgroup of ${\displaystyle G}$ containing every element of ${\displaystyle S}$, which is equal to the intersection over all subgroups containing the elements of ${\displaystyle S}$; equivalently, ${\displaystyle \langle S\rangle }$ is the subgroup of all elements of ${\displaystyle G}$ that can be expressed as the finite product of elements in ${\displaystyle S}$ and their inverses. (Note that inverses are only needed if the group is infinite; in a finite group, the inverse of an element can be expressed as a power of that element.)

In mathematics, especially in the area of abstract algebra that studies infinite groups, the adverb virtually is used to modify a property so that it need only hold for a subgroup of finite index. Given a property P, the group G is said to be virtually P if there is a finite index subgroup ${\displaystyle H\leq G}$ such that H has property P.

Common uses for this would be when P is abelian, nilpotent, solvable or free. For example, virtually solvable groups are one of the two alternatives in the Tits alternative, while Gromov's theorem states that the finitely generated groups with polynomial growth are precisely the finitely generated virtually nilpotent groups.

The Awori is a subgroup of the Yoruba people of (heterogeneous origin) speaking a dialect of the Yoruba language.

In mathematics, an embedding (or imbedding) is one instance of some mathematical structure contained within another instance, such as a group that is a subgroup.

When some object ${\displaystyle X}$ is said to be embedded in another object ${\displaystyle Y}$, the embedding is given by some injective and structure-preserving map ${\displaystyle f:X\rightarrow Y}$. The precise meaning of "structure-preserving" depends on the kind of mathematical structure of which ${\displaystyle X}$ and ${\displaystyle Y}$ are instances. In the terminology of category theory, a structure-preserving map is called a morphism.

Algebraic topology is a branch of mathematics that uses tools from abstract algebra to study topological spaces. The basic goal is to find algebraic invariants that classify topological spaces up to homeomorphism, though usually most classify up to homotopy equivalence.

Although algebraic topology primarily uses algebra to study topological problems, using topology to solve algebraic problems is sometimes also possible. Algebraic topology, for example, allows for a convenient proof that any subgroup of a free group is again a free group.

Gurans (Russian: Гураны) are a Slavo-Mongolic ethnic or subgroup, mainly from Transbaikalia, that formed as a result of mixed marriages between Russians and Buryats (and other indigenous ethnic groups).

In mathematics, the isometry group of a metric space is the set of all bijective isometries (that is, bijective, distance-preserving maps) from the metric space onto itself, with the function composition as group operation. Its identity element is the identity function. The elements of the isometry group are sometimes called motions of the space.

Every isometry group of a metric space is a subgroup of isometries. It represents in most cases a possible set of symmetries of objects/figures in the space, or functions defined on the space. See symmetry group.

In mathematics, especially group theory, the centralizer (also called commutant) of a subset S in a group G is the set ${\displaystyle \operatorname {C} _{G}(S)}$ of elements of G that commute with every element of S, or equivalently, the set of elements ${\displaystyle g\in G}$ such that conjugation by ${\displaystyle g}$ leaves each element of S fixed. The normalizer of S in G is the set of elements ${\displaystyle \mathrm {N} _{G}(S)}$ of G that satisfy the weaker condition of leaving the set ${\displaystyle S\subseteq G}$ fixed under conjugation. The centralizer and normalizer of S are subgroups of G. Many techniques in group theory are based on studying the centralizers and normalizers of suitable subsets S.

Suitably formulated, the definitions also apply to semigroups.

The Rubik's Cube group ${\displaystyle (G,\cdot )}$ represents the mathematical structure of the Rubik's Cube mechanical puzzle. Each element of the set ${\displaystyle G}$ corresponds to a cube move, which is the effect of any sequence of rotations of the cube's faces. With this representation, not only can any cube move be represented, but any position of the cube as well, by detailing the cube moves required to rotate the solved cube into that position. Indeed with the solved position as a starting point, there is a one-to-one correspondence between each of the legal positions of the Rubik's Cube and the elements of ${\displaystyle G}$. The group operation ${\displaystyle \cdot }$ is the composition of cube moves, corresponding to the result of performing one cube move after another.

The Rubik's Cube is constructed by labeling each of the 48 non-center facets with the integers 1 to 48. Each configuration of the cube can be represented as a permutation of the labels 1 to 48, depending on the position of each facet. Using this representation, the solved cube is the identity permutation which leaves the cube unchanged, while the twelve cube moves that rotate a layer of the cube 90 degrees are represented by their respective permutations. The Rubik's Cube group is the subgroup of the symmetric group ${\displaystyle S_{48}}$ generated by the six permutations corresponding to the six clockwise cube moves. With this construction, any configuration of the cube reachable through a sequence of cube moves is within the group. Its operation ${\displaystyle \cdot }$ refers to the composition of two permutations; within the cube, this refers to combining two sequences of cube moves together, doing one after the other. The Rubik's Cube group is non-abelian as composition of cube moves is not commutative; doing a sequence of cube moves in a different order can result in a different configuration.

In mathematics, a topological group G is called a discrete group if there is no limit point in it (i.e., for each element in G, there is a neighborhood which only contains that element). Equivalently, the group G is discrete if and only if its identity is isolated.

A subgroup H of a topological group G is a discrete subgroup if H is discrete when endowed with the subspace topology from G. In other words there is a neighbourhood of the identity in G containing no other element of H. For example, the integers, Z, form a discrete subgroup of the reals, R (with the standard metric topology), but the rational numbers, Q, do not.

In abstract algebra, the symmetric group defined over any set is the group whose elements are all the bijections from the set to itself, and whose group operation is the composition of functions. In particular, the finite symmetric group ${\displaystyle \mathrm {S} _{n}}$ defined over a finite set of ${\displaystyle n}$ symbols consists of the permutations that can be performed on the ${\displaystyle n}$ symbols. Since there are ${\displaystyle n!}$ (${\displaystyle n}$ factorial) such permutation operations, the order (number of elements) of the symmetric group ${\displaystyle \mathrm {S} _{n}}$ is ${\displaystyle n!}$.

Although symmetric groups can be defined on infinite sets, this article focuses on the finite symmetric groups: their applications, their elements, their conjugacy classes, a finite presentation, their subgroups, their automorphism groups, and their representation theory. For the remainder of this article, "symmetric group" will mean a symmetric group on a finite set.

In mathematics, specifically group theory, the index of a subgroup H in a group G is the number of left cosets of H in G, or equivalently, the number of right cosets of H in G.The index is denoted ${\displaystyle |G:H|}$ or ${\displaystyle [G:H]}$ or ${\displaystyle (G:H)}$.Because G is the disjoint union of the left cosets and because each left coset has the same size as H, the index is related to the orders of the two groups by the formula

(interpret the quantities as cardinal numbers if some of them are infinite).Thus the index ${\displaystyle |G:H|}$ measures the "relative sizes" of G and H.

In mathematics, specifically group theory, a subgroup H of a group G may be used to decompose the underlying set of G into disjoint, equal-size subsets called cosets. There are left cosets and right cosets. Cosets (both left and right) have the same number of elements (cardinality) as does H. Furthermore, H itself is both a left coset and a right coset. The number of left cosets of H in G is equal to the number of right cosets of H in G. This common value is called the index of H in G and is usually denoted by [G : H].

Cosets are a basic tool in the study of groups; for example, they play a central role in Lagrange's theorem that states that for any finite group G, the number of elements of every subgroup H of G divides the number of elements of G. Cosets of a particular type of subgroup (a normal subgroup) can be used as the elements of another group called a quotient group or factor group. Cosets also appear in other areas of mathematics such as vector spaces and error-correcting codes.

In mathematics, a permutation group is a group G whose elements are permutations of a given set M and whose group operation is the composition of permutations in G (which are thought of as bijective functions from the set M to itself). The group of all permutations of a set M is the symmetric group of M, often written as Sym(M). The term permutation group thus means a subgroup of the symmetric group. If M = {1, 2, ..., n} then Sym(M) is usually denoted by S_n, and may be called the symmetric group on n letters.

By Cayley's theorem, every group is isomorphic to some permutation group.