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The split stephas amplification matrixOn a common directional eigenvector its eigenvalue is $(1+\mu {\lambda }_p)/(1-\mu {\lambda }_q)$.

For $Y=n^{-1}\mathrm{Bin}(n,p)$, the score and information areConsequently one Fisher-scoring step sends every interior starting value directly to the MLE $\hat{p}=Y$.

If a continuous function $f$ satisfiesfor every smooth compactly supported test function $\eta$, then $f=0$ on $(a,b)$.

An integral matrix satisfying $A^2+A+I=0$ makes ${\mathbb{Z}}^n$ a module over the Eisenstein integers by letting the primitive cube root act as $A$. This module is finitely generated and torsion-free, hence free. Since the Eisenstein integers have integer rank two, such matrices exist only for $n=2m$; for that dimension every one is integrally conjugate to

An orthonormal eigenbasis of a linear operator is an orthonormal basis consisting of eigenvectors. Each vector can be reconstructed from its scalar components along those mutually perpendicular unit directions. With the convention that the inner product is linear in its first argument,The finite-dimensional spectral theorem supplies such a basis for a self-adjoint operator. In its two-dimensional example, the coordinates of $x=(1,0{)}^T$ are $1/\sqrt{2}$ along $e_{+}$ and $-1/\sqrt{2}$ along $e_{-}$. The operator multiplies those coordinates by $3$ and $1$, and reconstruction gives $Ax=(2,1{)}^T$.

Repeated eigenvalues permit different orthonormal choices within one eigenspace, so the basis need not be unique. The spectral projection of a self-adjoint matrix onto that entire eigenspace is unique: it keeps the geometrically meaningful component without choosing individual axes inside it.

The $E_7$ Coxeter graph is the simply-laced seven-vertex tree whose three arms have lengths $1$, $2$, and $3$. Its Coxeter Gram matrix is positive definite and has determinant $2$.

The character group $\hat{G}$ consists of the group homomorphisms $\gamma :G\to {\mathbb{C}}^{\times }$. Pointwise multiplication makes it a finite abelian group isomorphic to $G$.

In the Category of sets, filtered colimits commute with finite limits. Elements in a finite limiting diagram involve only finitely many representatives and finitely many equalities, all of which can be realized at one common stage of a filtered diagram.

A category is weakly filtered when every finite connected diagram in it admits a cocone. Equivalently, each of its connected components is a filtered category.

For a morphism of schemes $f:X\to Y$ and a point $y\in Y$, the scheme-theoretic fiber is the fiber product $X{\times }_Y\mathrm{Spec}\kappa (y)$. It remembers multiplicities and nilpotents that the underlying set-theoretic inverse image cannot detect.

Its underlying fiber is enriched with local-ring and multiplicity information.

The Fermi sea is the zero-temperature many-fermion state in which every one-particle state below the Fermi energy is occupied and every state above it is empty.

For activator diffusion $D$, local linear decay $r$, and coupling $\rho (u-v)$, eliminating the fast inhibitor givesIts pattern-forming threshold is

Choose an orthonormal basis of $T_{p}M$ and put $e(\theta )=(\cos \theta ,\sin \theta )$. Away from the centre and cut locus,defines geodesic polar coordinates centred at $p$.

A normal neighbourhood of $p$ is the diffeomorphic image under ${\exp }_p$ of a star-shaped neighbourhood of $0$ in $T_{p}M$. In a sufficiently small normal ball, radial geodesics from $p$ uniquely minimize length.

The domain of ${\exp }_p$ is the star-shaped open setSmooth dependence for ordinary differential equations makes $(p,v)\mapsto {\exp }_p(v)$ smooth on its open domain in $TM$.

If $N$ is geometric on $\{1,2,\dots \}$ with parameter $p$, independently of unit-rate exponential variables $S_i$, thenis exponential with rate $p$. Its moment-generating function is $p/(p-\theta )$ for $\theta <p$.

For independent exponential variables $S_i$ of rates $q_i$ and $Q={\sum }_i{q}_i$, let $T={\min }_i{S}_i$ and let $K$ be the minimizing index. ThenConsequently $T$ is exponential with rate $Q$, $\mathbb{P}(K=k)=q_k/Q$, and $K$ and $T$ are independent.

If $A$ and $B$ are independent exponential variables with the same rate, then $A/(A+B)$ is uniform on $(0,1)$ and is independent of $A+B$.

If $T\sim \mathrm{Exp}(\mu )$, thenThus an exponential remaining lifetime has the same law regardless of the elapsed lifetime.

For $S_t=S_0{e}^{\mu t+\sigma W_t}$, shifting Brownian drift bymakes $S_t=S_0{e}^{(r-{\sigma }^2/2)t+\sigma W_t^Q}$ under an equivalent martingale measure $Q$. The discounted stock is then a martingale.