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Physlib.SpaceAndTime.Space.IsDistBounded

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definition

ff is distribution-bounded

#IsDistBounded

Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. The predicate `IsDistBounded f` holds if ff is almost everywhere strongly measurable with respect to the volume measure and there exists a finite natural number nn such that the norm of ff is bounded by a sum of the form: \[ \|f(x)\| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i} \] where for each i{1,,n}i \in \{1, \dots, n\}, the coefficient cic_i is a non-negative real number (ci0c_i \ge 0), gig_i is a vector in Space d\text{Space } d, and the exponent pip_i is an integer satisfying pi(d1)p_i \ge -(d - 1).

theorem

IsDistBounded f\text{IsDistBounded } f implies ff is almost everywhere strongly measurable

#aestronglyMeasurable

Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (satisfies IsDistBounded f\text{IsDistBounded } f), then ff is almost everywhere strongly measurable with respect to the volume measure on Space d\text{Space } d.

theorem

If ff is distribution-bounded, then xη(x)f(x)x \mapsto \eta(x) \cdot f(x) is almost everywhere strongly measurable

#aeStronglyMeasurable_schwartzMap_smul

Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (satisfies `IsDistBounded f`), then for any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}), the function mapping xSpace dx \in \text{Space } d to the scalar product η(x)f(x)\eta(x) \cdot f(x) is almost everywhere strongly measurable with respect to the volume measure.

theorem

AE Strong Measurability of x(Dη(x)y)f(x)x \mapsto (D\eta(x) \cdot y) f(x) for Distribution-Bounded ff

#aeStronglyMeasurable_fderiv_schwartzMap_smul

Let dd be a natural number and f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (satisfies `IsDistBounded f`), then for any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}) and any vector ySpace dy \in \text{Space } d, the function x(Dη(x)y)f(x)x \mapsto (D\eta(x) \cdot y) f(x) is almost everywhere strongly measurable with respect to the volume measure, where Dη(x)yD\eta(x) \cdot y denotes the Fréchet derivative of η\eta at xx evaluated in the direction yy.

theorem

If ff is distribution-bounded, then x1(1+x)rf(x)x \mapsto \frac{1}{(1 + \|x\|)^r} f(x) is almost everywhere strongly measurable

#aeStronglyMeasurable_inv_pow

Let dd and rr be natural numbers. Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (meaning it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i}), then the function x1(1+x)rf(x)x \mapsto \frac{1}{(1 + \|x\|)^r} f(x) is almost everywhere strongly measurable with respect to the volume measure on Space d\text{Space } d.

theorem

A distribution-bounded function scaled by a space-time Schwartz map is AE strongly measurable

#aeStronglyMeasurable_time_schwartzMap_smul

Let dd be a natural number and f:Space dFf: \text{Space } d \to F be a distribution-bounded function mapping into a normed space FF. For any Schwartz map ηS(Time×Space d,R)\eta \in \mathcal{S}(\text{Time} \times \text{Space } d, \mathbb{R}), the function (t,x)η(t,x)f(x)(t, x) \mapsto \eta(t, x) \cdot f(x) is almost everywhere strongly measurable with respect to the volume measure on Time×Space d\text{Time} \times \text{Space } d.

theorem

Distribution-bounded functions are integrable against Schwartz maps

#integrable_space

Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (satisfies `IsDistBounded f`), then for any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}), the function xη(x)f(x)x \mapsto \eta(x) \cdot f(x) is integrable on Space d\text{Space } d with respect to the volume measure.

theorem

The product of a distribution-bounded function and a Schwartz map is integrable

#integrable_space_mul

Let f:Space dRf: \text{Space } d \to \mathbb{R} be a real-valued function on a dd-dimensional Euclidean space. If ff is distribution-bounded (satisfies `IsDistBounded f`), then for any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}), the product function xη(x)f(x)x \mapsto \eta(x) f(x) is integrable with respect to the volume measure.

theorem

Distribution-bounded functions are integrable against the derivatives of Schwartz maps

#integrable_space_fderiv

Let dd be a natural number and let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (satisfies `IsDistBounded f`), then for any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}) and any vector ySpace dy \in \text{Space } d, the function x(Dη(x)y)f(x)x \mapsto (D\eta(x)y) \cdot f(x) is integrable with respect to the volume measure, where Dη(x)yD\eta(x)y denotes the Fréchet derivative of η\eta at xx applied to the vector yy.

theorem

Product of a distribution-bounded function and the derivative of a Schwartz map is integrable

#integrable_space_fderiv_mul

Let f:Space dRf: \text{Space } d \to \mathbb{R} be a distribution-bounded function on a dd-dimensional Euclidean space. For any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}) and any vector ySpace dy \in \text{Space } d, the function x(Dη(x)y)f(x)x \mapsto (D\eta(x)y) \cdot f(x) is integrable with respect to the volume measure on Space d\text{Space } d, where Dη(x)yD\eta(x)y denotes the Fréchet derivative of η\eta at xx applied to the vector yy.

instance

Temperate growth of μ1\mu_1 and μ2\mu_2 implies temperate growth of μ1×μ2\mu_1 \times \mu_2

#instHasTemperateGrowthProdProdOfOpensMeasurableSpace

Let D1D_1 and D2D_2 be normed additive commutative groups equipped with measurable structures. If μ1\mu_1 and μ2\mu_2 are measures on D1D_1 and D2D_2 respectively that both have temperate growth, then the product measure μ1×μ2\mu_1 \times \mu_2 on the product space D1×D2D_1 \times D_2 also has temperate growth, provided that the product space is an opens-measurable space (i.e., its σ\sigma-algebra is generated by its open sets).

theorem

Integrability of distribution-bounded functions against space-time Schwartz maps

#integrable_time_space

Let dd be a natural number and f:Space dFf: \text{Space } d \to F be a distribution-bounded function mapping into a normed space FF. For any Schwartz map η\eta in the space S(Time×Space d,R)\mathcal{S}(\text{Time} \times \text{Space } d, \mathbb{R}), the function (t,x)η(t,x)f(x)(t, x) \mapsto \eta(t, x) \cdot f(x) is integrable over Time×Space d\text{Time} \times \text{Space } d with respect to the volume measure.

theorem

If ff is distribution-bounded, then x1(1+x)rf(x)x \mapsto \frac{1}{(1 + \|x\|)^r} f(x) is integrable for some rNr \in \mathbb{N}

#integrable_mul_inv_pow

Let dd be a natural number and f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (i.e., it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i} where pi(d1)p_i \ge -(d - 1)), then there exists a natural number rr such that the function \[ x \mapsto \frac{1}{(1 + \|x\|)^r} f(x) \] is integrable with respect to the volume measure on Space d\text{Space } d.

theorem

Integral of a distribution-bounded function is bounded by Schwartz seminorms

#integral_mul_schwartzMap_bounded

Let f:Space dFf: \text{Space } d \to F be a distribution-bounded function from a dd-dimensional Euclidean space to a normed space FF. Then there exist a finite set of indices sN×Ns \subset \mathbb{N} \times \mathbb{N} and a non-negative real constant C0C \ge 0 such that for any Schwartz map ηS(Space d,R)\eta \in \mathcal{S}(\text{Space } d, \mathbb{R}), the norm of the integral of ff against η\eta is bounded by the supremum of a finite family of Schwartz seminorms: \[ \left\| \int_{\text{Space } d} \eta(x) f(x) \, dx \right\| \le C \cdot \max_{(k, \ell) \in s} p_{k, \ell}(\eta) \] where pk,p_{k, \ell} denotes the (k,)(k, \ell)-th seminorm in the standard family of seminorms for the Schwartz space S(Space d,R)\mathcal{S}(\text{Space } d, \mathbb{R}).

theorem

The zero function is distribution-bounded

#zero

For any dimension dd, the constant zero function f:Space dFf: \text{Space } d \to F (where f(x)=0f(x) = 0 for all xSpace dx \in \text{Space } d) is distribution-bounded.

theorem

The sum of two distribution-bounded functions is distribution-bounded

#add

Let f,g:Space dFf, g: \text{Space } d \to F be two functions from a dd-dimensional Euclidean space to a normed space FF. If both ff and gg are distribution-bounded (satisfying the predicate `IsDistBounded`), then their sum f+gf + g is also distribution-bounded.

theorem

The Pointwise Sum of Distribution-Bounded Functions is Distribution-Bounded

#fun_add

Let f,g:Space dFf, g: \text{Space } d \to F be functions from a dd-dimensional Euclidean space to a normed space FF. If both ff and gg are distribution-bounded (satisfying the predicate `IsDistBounded`), then their pointwise sum xf(x)+g(x)x \mapsto f(x) + g(x) is also distribution-bounded.

theorem

Finite sums of distribution-bounded functions are distribution-bounded

#sum

Let dd be a natural number and ss be a finite set of indices. Let fi:Space dFf_i: \text{Space } d \to F be a family of functions from a dd-dimensional Euclidean space to a normed space FF indexed by isi \in s. If for every isi \in s, the function fif_i is distribution-bounded, then their sum isfi\sum_{i \in s} f_i is also distribution-bounded. A function ff is distribution-bounded if it is almost everywhere strongly measurable and there exist constants cj0c_j \ge 0, vectors gjSpace dg_j \in \text{Space } d, and integers pj(d1)p_j \ge -(d - 1) such that f(x)j=1ncjx+gjpj\|f(x)\| \le \sum_{j=1}^n c_j \|x + g_j\|^{p_j}.

theorem

The Pointwise Finite Sum of Distribution-Bounded Functions is Distribution-Bounded

#sum_fun

Let dd be a natural number and ss be a finite set of indices. Let fi:Space dFf_i: \text{Space } d \to F be a family of functions from a dd-dimensional Euclidean space to a normed space FF indexed by isi \in s. If for every isi \in s, the function fif_i is distribution-bounded, then their pointwise sum xisfi(x)x \mapsto \sum_{i \in s} f_i(x) is also distribution-bounded. A function ff is distribution-bounded if it is almost everywhere strongly measurable and there exist a finite number of constants cj0c_j \ge 0, vectors gjSpace dg_j \in \text{Space } d, and integers pj(d1)p_j \ge -(d - 1) such that: \[ \|f(x)\| \le \sum_{j=1}^n c_j \|x + g_j\|^{p_j} \]

theorem

Scalar multiplication preserves distribution-boundedness

#const_smul

Let dd be a natural number and FF be a normed space over R\mathbb{R}. If a function f:Space dFf : \text{Space } d \to F is distribution-bounded, then for any constant cRc \in \mathbb{R}, the scalar multiple cfc \cdot f is also distribution-bounded. A function is distribution-bounded if it is almost everywhere strongly measurable and there exist constants ci0c_i \ge 0, vectors giSpace dg_i \in \text{Space } d, and integers pi(d1)p_i \ge -(d - 1) such that its norm is bounded by a finite sum: \[ \|f(x)\| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i} \]

theorem

Negation preserves distribution-boundedness

#neg

Let dd be a natural number and FF be a normed space over R\mathbb{R}. If a function f:Space dFf : \text{Space } d \to F is distribution-bounded, then its negation xf(x)x \mapsto -f(x) is also distribution-bounded. A function is distribution-bounded if it is almost everywhere strongly measurable and there exist constants ci0c_i \ge 0, vectors giSpace dg_i \in \text{Space } d, and integers pi(d1)p_i \ge -(d - 1) such that its norm is bounded by a finite sum: \[ \|f(x)\| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i} \]

theorem

Scalar multiplication of a distribution-bounded function is distribution-bounded

#const_fun_smul

Let dd be a natural number and FF be a normed space over R\mathbb{R}. If a function f:Space dFf : \text{Space } d \to F is distribution-bounded, then for any constant cRc \in \mathbb{R}, the function xcf(x)x \mapsto c \cdot f(x) is also distribution-bounded. A function ff is distribution-bounded if it is almost everywhere strongly measurable and there exists a finite sum such that f(x)i=1ncix+gipi\|f(x)\| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i}, where ci0c_i \ge 0, giSpace dg_i \in \text{Space } d, and pi(d1)p_i \ge -(d - 1).

theorem

Constant multiplication preserves distribution-boundedness

#const_mul_fun

Let dd be a natural number. If a function f:Space dRf: \text{Space } d \to \mathbb{R} is distribution-bounded, then for any constant cRc \in \mathbb{R}, the function xcf(x)x \mapsto c f(x) is also distribution-bounded. A function ff is distribution-bounded if it is almost everywhere strongly measurable and there exists a finite natural number nn such that its norm is bounded by a sum of the form: \[ \|f(x)\| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i} \] where for each i{1,,n}i \in \{1, \dots, n\}, the coefficient cic_i is a non-negative real number (ci0c_i \ge 0), gig_i is a vector in Space d\text{Space } d, and the exponent pip_i is an integer satisfying pi(d1)p_i \ge -(d - 1).

theorem

Multiplication by a constant preserves distribution-boundedness

#mul_const_fun

Let dd be a natural number and f:Space dRf: \text{Space } d \to \mathbb{R} be a function. If ff is distribution-bounded, then for any constant cRc \in \mathbb{R}, the function xf(x)cx \mapsto f(x) \cdot c is also distribution-bounded.

theorem

Components of a Distribution-Bounded Function are Distribution-Bounded

#pi_comp

Let f:Space dRnf: \text{Space } d \to \mathbb{R}^n be a function from a dd-dimensional space to an nn-dimensional Euclidean space. If ff is distribution-bounded, then for any index j{1,,n}j \in \{1, \dots, n\}, the jj-th component function xf(x)jx \mapsto f(x)_j is also distribution-bounded.

theorem

Components of a distribution-bounded Lorentz vector function are distribution-bounded

#vector_component

Let f:Space dVectornf: \text{Space } d \to \text{Vector}_n be a function from a dd-dimensional Euclidean space to the space of nn-dimensional Lorentz vectors. If ff is distribution-bounded, then for any index jFin 1Fin nj \in \text{Fin } 1 \oplus \text{Fin } n, the scalar-valued function xf(x)jx \mapsto f(x)_j (the jj-th component of f(x)f(x)) is also distribution-bounded.

theorem

ff is distribution-bounded implies xf(x+c)x \mapsto f(x + c) is distribution-bounded

#comp_add_right

Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional space to a normed space FF. If ff is distribution-bounded (satisfies the predicate `IsDistBounded f`), then for any vector cSpace dc \in \text{Space } d, the function xf(x+c)x \mapsto f(x + c) is also distribution-bounded.

theorem

ff is distribution-bounded implies xf(xc)x \mapsto f(x - c) is distribution-bounded

#comp_sub_right

Let f:Space dFf: \text{Space } d \to F be a function from a dd-dimensional Euclidean space to a normed space FF. If ff is distribution-bounded (satisfies the predicate `IsDistBounded f`), then for any vector cSpace dc \in \text{Space } d, the shifted function xf(xc)x \mapsto f(x - c) is also distribution-bounded.

theorem

Norm Equality preserves Distribution-Boundedness

#congr

Let f:Space dFf: \text{Space } d \to F be a distribution-bounded function and g:Space dFg: \text{Space } d \to F' be an almost everywhere strongly measurable function, where FF and FF' are normed spaces. If g(x)=f(x)\|g(x)\| = \|f(x)\| for all xSpace dx \in \text{Space } d, then gg is distribution-bounded.

theorem

If g(x)f(x)\|g(x)\| \leq \|f(x)\| and ff is distribution-bounded, then gg is distribution-bounded

#mono

Let dd be a natural number, and let f:Space dFf: \text{Space } d \to F and g:Space dFg: \text{Space } d \to F' be functions mapping from a dd-dimensional Euclidean space into normed spaces FF and FF', respectively. If ff is distribution-bounded, gg is almost everywhere strongly measurable, and the norm of gg is point-wise bounded by the norm of ff (i.e., g(x)f(x)\|g(x)\| \le \|f(x)\| for all xSpace dx \in \text{Space } d), then gg is also distribution-bounded.

theorem

If ff is distribution-bounded, then xf(x),yx \mapsto \langle f(x), y \rangle is distribution-bounded

#inner_left

Let f:Space dRnf: \text{Space } d \to \mathbb{R}^n be a distribution-bounded function. This means that ff is almost everywhere strongly measurable and its norm is bounded by a finite sum of the form \[ \|f(x)\| \le \sum_{i=1}^k c_i \|x + g_i\|^{p_i} \] where ci0c_i \ge 0, giSpace dg_i \in \text{Space } d, and the integers pip_i satisfy pi(d1)p_i \ge -(d - 1). For any constant vector yRny \in \mathbb{R}^n, the scalar-valued function mapping xx to the real inner product f(x),y\langle f(x), y \rangle is also distribution-bounded.

theorem

Scalar multiplication by a constant vector preserves distribution-boundedness

#smul_const

Let dd be a natural number and FF be a normed space over R\mathbb{R}. If c:Space dRc: \text{Space } d \to \mathbb{R} is a distribution-bounded function, then for any constant vector fFf \in F, the function mapping xSpace dx \in \text{Space } d to the scalar product c(x)fc(x) \cdot f is also distribution-bounded.

theorem

Constant functions are distribution-bounded

#const

Let dd be a natural number and FF be a normed space. For any element fFf \in F, the constant function c:Space dFc: \text{Space } d \to F defined by c(x)=fc(x) = f for all xSpace dx \in \text{Space } d is distribution-bounded (satisfies `IsDistBounded`).

theorem

xn\|x\|^n is distribution-bounded for n(d1)n \ge -(d-1)

#pow

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any integer nn such that n(d1)n \ge -(d - 1), the function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=xnf(x) = \|x\|^n is distribution-bounded.

theorem

xgn\|x - g\|^n is distribution-bounded for n(d1)n \ge -(d - 1)

#pow_shift

For any dimension dNd \in \mathbb{N}, integer exponent nZn \in \mathbb{Z} such that n(d1)n \ge -(d - 1), and any vector gSpace dg \in \text{Space } d, the function mapping xx to xgn\|x - g\|^n is distribution-bounded (satisfies `IsDistBounded`).

theorem

xg1\|x - g\|^{-1} is distribution-bounded for d2d \ge 2

#inv_shift

For any dimension d2d \ge 2 and any vector gSpace dg \in \text{Space } d, the function mapping xSpace dx \in \text{Space } d to the inverse Euclidean norm xg1\|x - g\|^{-1} is distribution-bounded (satisfies the property `IsDistBounded`).

theorem

xn\|x\|^n is distribution-bounded for nNn \in \mathbb{N}

#nat_pow

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any natural number nNn \in \mathbb{N}, the function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=xnf(x) = \|x\|^n is distribution-bounded.

theorem

(x+a)n(\|x\| + a)^n is distribution-bounded for nNn \in \mathbb{N}

#norm_add_nat_pow

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any natural number nNn \in \mathbb{N} and any real number aRa \in \mathbb{R}, the function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=(x+a)nf(x) = (\|x\| + a)^n is distribution-bounded (satisfies the predicate `IsDistBounded`). Here, \|\cdot\| denotes the Euclidean norm on Space d\text{Space } d.

theorem

(x+a)n(\|x\| + a)^n is distribution-bounded for a>0a > 0 and nZn \in \mathbb{Z}

#norm_add_pos_nat_zpow

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any integer nZn \in \mathbb{Z} and any real number a>0a > 0, the function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=(x+a)nf(x) = (\|x\| + a)^n is distribution-bounded (satisfies the predicate `IsDistBounded`). Here, \|\cdot\| denotes the Euclidean norm on Space d\text{Space } d.

theorem

xgn\|x - g\|^n is distribution-bounded for nNn \in \mathbb{N}

#nat_pow_shift

For any dimension dNd \in \mathbb{N}, natural number exponent nNn \in \mathbb{N}, and vector gSpace dg \in \text{Space } d, the function mapping xx to xgn\|x - g\|^n is distribution-bounded (satisfies the predicate `IsDistBounded`).

theorem

xg\|x - g\| is distribution-bounded

#norm_sub

For any dimension dNd \in \mathbb{N} and any vector gSpace dg \in \text{Space } d, the function mapping xx to the Euclidean norm xg\|x - g\| is distribution-bounded.

theorem

x+g\|x + g\| is distribution-bounded

#norm_add

For any dimension dNd \in \mathbb{N} and any vector gSpace dg \in \text{Space } d, the function mapping xx to the Euclidean norm x+g\|x + g\| is distribution-bounded (satisfies the predicate `IsDistBounded`).

theorem

x1\|x\|^{-1} is distribution-bounded for d2d \ge 2

#inv

For any natural number nn, let d=n+2d = n + 2 be the dimension of the Euclidean space Space d\text{Space } d. The function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=x1f(x) = \|x\|^{-1} is distribution-bounded.

theorem

x\|x\| is distribution-bounded

#norm

Let Space d\text{Space } d be a dd-dimensional Euclidean space. The function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=xf(x) = \|x\|, which maps each vector xx to its Euclidean norm, is distribution-bounded.

theorem

logx\log \|x\| is distribution-bounded for d2d \ge 2

#log_norm

For any natural number dd, let D=d+2D = d + 2 be the dimension of the Euclidean space Space D\text{Space } D. The function f:Space DRf: \text{Space } D \to \mathbb{R} defined by f(x)=logxf(x) = \log \|x\| is distribution-bounded.

theorem

xnx\|x\|^n x is distribution-bounded for n(d1)1n \ge -(d-1)-1

#zpow_smul_self

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any integer nn such that n(d1)1n \ge -(d-1)-1, the function f:Space dSpace df: \text{Space } d \to \text{Space } d defined by f(x)=xnxf(x) = \|x\|^n x is distribution-bounded.

theorem

xnrepr(x)\|x\|^n \text{repr}(x) is distribution-bounded for n(d1)1n \ge -(d-1)-1

#zpow_smul_repr_self

Let Space d\text{Space } d be a dd-dimensional Euclidean space and let repr(x)\text{repr}(x) denote the coordinate representation of a vector xx with respect to the standard orthonormal basis. For any integer nn such that n(d1)1n \ge -(d - 1) - 1, the function f(x)=xnrepr(x)f(x) = \|x\|^n \cdot \text{repr}(x) is distribution-bounded.

theorem

xynrepr(xy)\|x - y\|^n \text{repr}(x - y) is distribution-bounded for n(d1)1n \ge -(d-1)-1

#zpow_smul_repr_self_sub

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any vector ySpace dy \in \text{Space } d and any integer nn such that n(d1)1n \ge -(d - 1) - 1, the function mapping xSpace dx \in \text{Space } d to xynrepr(xy)\|x - y\|^n \cdot \text{repr}(x - y) is distribution-bounded. Here, repr(v)\text{repr}(v) denotes the coordinate representation of a vector vv with respect to the standard orthonormal basis of Space d\text{Space } d.

theorem

xnx\|x\|^{-n} x is distribution-bounded for n(d1)1-n \ge -(d-1)-1

#inv_pow_smul_self

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any natural number nn such that n(d1)1-n \ge -(d - 1) - 1, the function f:Space dSpace df: \text{Space } d \to \text{Space } d defined by f(x)=xnxf(x) = \|x\|^{-n} x is distribution-bounded.

theorem

xnbasis.repr(x)\|x\|^{-n} \text{basis.repr}(x) is distribution-bounded for n(d1)1-n \ge -(d-1)-1

#inv_pow_smul_repr_self

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any natural number nn such that n(d1)1-n \ge -(d - 1) - 1, the function f(x)=xnbasis.repr(x)f(x) = \|x\|^{-n} \cdot \text{basis.repr}(x), where basis.repr(x)\text{basis.repr}(x) denotes the coordinate representation of the vector xx with respect to the standard orthonormal basis, is distribution-bounded.

theorem

xx+cp\|x\| \cdot \|x + c\|^p is distribution-bounded

#norm_smul_nat_pow

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any natural number pNp \in \mathbb{N} and any vector cSpace dc \in \text{Space } d, the function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=xx+cpf(x) = \|x\| \cdot \|x + c\|^p is distribution-bounded. (A function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i} where pi(d1)p_i \ge -(d - 1)).

theorem

xx+cp\|x\| \cdot \|x + c\|^p is distribution-bounded for p(d1)p \ge -(d - 1)

#norm_smul_zpow

Let Space d\text{Space } d be a dd-dimensional Euclidean space. For any vector cSpace dc \in \text{Space } d and any integer pp such that p(d1)p \ge -(d - 1), the function f:Space dRf: \text{Space } d \to \mathbb{R} defined by f(x)=xx+cpf(x) = \|x\| \cdot \|x + c\|^p is distribution-bounded. (A function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i} where pi(d1)p_i \ge -(d - 1)).

theorem

Multiplication by the norm x\|x\| preserves distribution-boundedness

#norm_smul_isDistBounded

Let dd be a natural number and FF be a normed space over R\mathbb{R}. If a function f:Space dFf: \text{Space } d \to F is distribution-bounded, then the function mapping xSpace dx \in \text{Space } d to xf(x)\|x\| f(x) is also distribution-bounded. A function ff is distribution-bounded if it is almost everywhere strongly measurable and there exists a finite natural number nn such that its norm is bounded by a sum of the form: \[ \|f(x)\| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i} \] where for each i{1,,n}i \in \{1, \dots, n\}, the coefficient cic_i is a non-negative real number, gig_i is a vector in Space d\text{Space } d, and the exponent pip_i is an integer satisfying pi(d1)p_i \ge -(d - 1).

theorem

Multiplication by x\|x\| preserves distribution-boundedness for real-valued functions

#norm_mul_isDistBounded

Let dd be a natural number and f:Space dRf: \text{Space } d \to \mathbb{R} be a real-valued function. If ff is distribution-bounded, then the function mapping xSpace dx \in \text{Space } d to xf(x)\|x\| f(x) is also distribution-bounded. A function ff is distribution-bounded if it is almost everywhere strongly measurable and there exists a finite natural number nn such that its absolute value is bounded by a sum of the form: \[ |f(x)| \le \sum_{i=1}^n c_i \|x + g_i\|^{p_i} \] where for each i{1,,n}i \in \{1, \dots, n\}, the coefficient cic_i is a non-negative real number, gig_i is a vector in Space d\text{Space } d, and the exponent pip_i is an integer satisfying pi(d1)p_i \ge -(d - 1).

theorem

Multiplication by a coordinate preserves distribution-boundedness

#component_smul_isDistBounded

Let dd be a natural number and FF be a normed space over R\mathbb{R}. If a function f:Space dFf: \text{Space } d \to F is distribution-bounded, then for any coordinate index i{0,,d1}i \in \{0, \dots, d-1\}, the function mapping xSpace dx \in \text{Space } d to the scalar product of its ii-th coordinate xix_i and the value f(x)f(x), given by xxif(x)x \mapsto x_i \cdot f(x), is also distribution-bounded.

theorem

Multiplication by a coordinate preserves distribution-boundedness for real-valued functions

#component_mul_isDistBounded

Let dd be a natural number and let f:Space dRf: \text{Space } d \to \mathbb{R} be a real-valued function. If ff is distribution-bounded, then for any coordinate index i{0,,d1}i \in \{0, \dots, d-1\}, the function mapping xx to xif(x)x_i f(x) is also distribution-bounded, where xix_i denotes the ii-th coordinate of the vector xx.

theorem

Scalar multiplication by xx preserves distribution-boundedness

#isDistBounded_smul_self

Let dd be a natural number and f:Space dRf: \text{Space } d \to \mathbb{R} be a real-valued function. If ff is distribution-bounded, then the vector-valued function mapping xSpace dx \in \text{Space } d to the scalar multiplication f(x)xf(x)x is also distribution-bounded.

theorem

If ff is distribution-bounded, then xf(x)repr(x)x \mapsto f(x) \cdot \text{repr}(x) is distribution-bounded

#isDistBounded_smul_self_repr

Let dd be a natural number and f:Space dRf: \text{Space } d \to \mathbb{R} be a distribution-bounded function. Then the function mapping xSpace dx \in \text{Space } d to the scalar-vector product f(x)repr(x)f(x) \cdot \text{repr}(x) is also distribution-bounded, where repr(x)\text{repr}(x) denotes the coordinate representation of xx with respect to the standard orthonormal basis of Space d\text{Space } d.

theorem

If ff is distribution-bounded, then xy,xf(x)x \mapsto \langle y, x \rangle f(x) is distribution-bounded

#isDistBounded_smul_inner

Let dd be a natural number and FF be a normed space over R\mathbb{R}. Suppose f:Space dFf: \text{Space } d \to F is a distribution-bounded function. For any fixed vector ySpace dy \in \text{Space } d, the function xy,xf(x)x \mapsto \langle y, x \rangle f(x), formed by scaling f(x)f(x) by the inner product of yy and xx, is also distribution-bounded. Recall that a function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i}, where ci0c_i \ge 0, giSpace dg_i \in \text{Space } d, and pi(d1)p_i \ge -(d - 1).

theorem

If xxf(x)x \mapsto \|x\| f(x) is distribution-bounded, then xy,xf(x)x \mapsto \langle y, x \rangle f(x) is distribution-bounded

#isDistBounded_smul_inner_of_smul_norm

Let dd be a natural number and FF be a normed space over R\mathbb{R}. Let f:Space dFf: \text{Space } d \to F be an almost everywhere strongly measurable function. If the function xxf(x)x \mapsto \|x\| \cdot f(x) is distribution-bounded, then for any fixed vector ySpace dy \in \text{Space } d, the function xy,xf(x)x \mapsto \langle y, x \rangle f(x) is also distribution-bounded. Recall that a function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i}, where ci0c_i \ge 0 and pi(d1)p_i \ge -(d - 1).

theorem

If ff is distribution-bounded, then xy,xf(x)x \mapsto \langle y, x \rangle f(x) is distribution-bounded

#isDistBounded_mul_inner

Let dd be a natural number and let f:Space dRf: \text{Space } d \to \mathbb{R} be a distribution-bounded function. For any fixed vector ySpace dy \in \text{Space } d, the function xy,xf(x)x \mapsto \langle y, x \rangle f(x), defined by the product of the inner product y,x\langle y, x \rangle and f(x)f(x), is also distribution-bounded. Recall that a function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i}, where ci0c_i \ge 0, giSpace dg_i \in \text{Space } d, and pi(d1)p_i \ge -(d - 1).

theorem

If ff is distribution-bounded, then xx,yf(x)x \mapsto \langle x, y \rangle f(x) is distribution-bounded

#isDistBounded_mul_inner'

Let dd be a natural number and let f:Space dRf: \text{Space } d \to \mathbb{R} be a distribution-bounded function. For any fixed vector ySpace dy \in \text{Space } d, the function xx,yf(x)x \mapsto \langle x, y \rangle f(x), defined as the product of the inner product of xx and yy with the value of f(x)f(x), is also distribution-bounded. Recall that a function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of terms of the form cix+gipic_i \|x + g_i\|^{p_i}, where ci0c_i \ge 0, giSpace dg_i \in \text{Space } d, and pi(d1)p_i \ge -(d - 1).

theorem

If xxf(x)x \mapsto \|x\| f(x) is distribution-bounded, then xy,xf(x)x \mapsto \langle y, x \rangle f(x) is distribution-bounded

#isDistBounded_mul_inner_of_smul_norm

Let dd be a natural number and let f:Space dRf: \text{Space } d \to \mathbb{R} be an almost everywhere strongly measurable function. If the function xxf(x)x \mapsto \|x\| f(x) is distribution-bounded, then for any fixed vector ySpace dy \in \text{Space } d, the function xy,xf(x)x \mapsto \langle y, x \rangle f(x) is also distribution-bounded. Recall that a function is distribution-bounded if it is almost everywhere strongly measurable and its norm is bounded by a finite sum of the form i=1ncix+gipi\sum_{i=1}^n c_i \|x + g_i\|^{p_i}, where ci0c_i \ge 0 and pi(d1)p_i \ge -(d - 1).

theorem

The function xy,xx2x \mapsto \langle y, x \rangle \|x\|^{-2} is distribution-bounded in dimension d+2d+2

#mul_inner_pow_neg_two

Let dd be a natural number and let Space(d+2)\text{Space}(d+2) be a Euclidean space of dimension d+2d+2. For any vector ySpace(d+2)y \in \text{Space}(d+2), the function f:Space(d+2)Rf: \text{Space}(d+2) \to \mathbb{R} defined by f(x)=y,xx2f(x) = \langle y, x \rangle \|x\|^{-2} is distribution-bounded.