Terminology & Translations

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binomial random graph 随机图

For n ≥ 0 and 0 ≤ p ≤ 1, G(n,p) is the random simple graph on a fixed labeled n-vertex set in which each possible edge is included independently with probability p.

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bipartite graph 二部图

A simple graph is bipartite if its vertex set admits a partition into two disjoint parts such that every edge has one endpoint in each part.

Birkhoff pointwise ergodic theorem Birkhoff遍历定理

For a probability-preserving $T$ and $f\in L^1(\mu)$, the averages $n^{-1}\sum_{j=0}^{n-1}f(T^jx)$ converge almost everywhere to $E[f\mid\mathcal I]$, with $\mathcal I$ the invariant sigma-algebra; for ergodic $T$ the…

bound variable occurrence 约束出现

An occurrence of a variable within the scope of a quantifier for that variable, bound by the nearest such quantifier.

bounded linear operator 有界线性算子

A linear map T between normed spaces is bounded when some finite C satisfies norm(Tx)<=C norm(x) for every domain vector x.

cardinality of a set 基数

In ZFC, the least ordinal bijective with a set; equality of cardinalities is equivalently existence of a bijection.

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Cartesian product 笛卡尔积

For sets A and B, the set of ordered pairs with first coordinate in A and second in B.

categorical colimit 余极限

For a small diagram, a cocone from which every compatible cocone factors by a unique map of vertices respecting all legs.

categorical coproduct 余积

An object with maps from a specified family such that each family of maps into any Y extends uniquely to a map from that object to Y.

categorical equalizer 等化子

For parallel f,g:A→B, a map e:E→A with fe=ge universal among maps with that equality.

categorical limit 极限

For a small diagram D:J→C, a cone through which every other cone factors by a unique vertex map respecting all legs.

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categorical product 积

Objects P with projections to a specified family such that every matching family of maps from any X arises uniquely from a map X→P.

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categorical pullback 拉回

For A→C←B, an object P with maps to A and B making the square commute and universal among such commuting pairs.

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category 范畴

Objects and directed morphisms with specified sources, targets, associative composition and a two-sided identity at each object.

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Cauchy integral formula 柯西积分公式

If f is holomorphic near the closed disk of radius r centered at a, then for every z in that disk's interior, f(z)=(2 pi i)^(-1) integral_{|w-a|=r} f(w)/(w-z) dw with counterclockwise orientation.

Cauchy sequence 基本列

A sequence x_n in a metric space is Cauchy if for every epsilon > 0 some N makes d(x_m,x_n) = N.

Cauchy–Riemann equations 柯西-黎曼方程

For f=u+iv on a plane domain, the Cauchy–Riemann equations are u_x=v_y and u_y=-v_x. Under C^1 regularity they characterize holomorphicity.

cellular homology 胞腔同调

For a CW complex, the homology of the chain complex with C_n=H_n(X^n,X^{n-1};Z), whose boundary is formed from the relative connecting map followed by projection to the next skeletal pair.

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central limit theorem 中心极限定理

The classical iid central limit theorem states that for real iid $X_j$ with mean $\mu$ and variance $0<\sigma^2<\infty$, $(\sum_{j=1}^n X_j-n\mu)/(\sigma\sqrt n)$ converges in distribution to $N(0,1)$.

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characteristic polynomial of a linear map 线性映射的特征多项式

For an endomorphism of an $n$-dimensional $F$-space, the basis-independent monic polynomial $\det(xI-A)$.

Chinese remainder theorem for integers 整数中国剩余定理

For pairwise coprime positive integers $m_1,\ldots,m_r$, any prescribed residues have a simultaneous integer solution unique modulo $\prod_i m_i$.

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chromatic number 色数

The chromatic number χ(G) of a finite simple graph is the least nonnegative integer k admitting a vertex coloring with k colors in which adjacent vertices receive different colors.

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class number of a number field 数域的类数

The finite cardinality $h_K=|\operatorname{Cl}(K)|$ of the ideal class group of a number field $K$.