当前位置: X-MOL 学术Theor. Comput. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Sensitivity, affine transforms and quantum communication complexity
Theoretical Computer Science ( IF 0.9 ) Pub Date : 2020-06-03 , DOI: 10.1016/j.tcs.2020.05.048
Krishnamoorthy Dinesh , Jayalal Sarma

In this paper, we study the Boolean function parameters sensitivity (s), block sensitivity (bs), and alternation (alt) under specially designed affine transforms and show several applications. For a function f:F2n{1,1}, and A=Mx+b for MF2n×n and bF2n, the result of the transformation g is defined as xF2n,g(x)=f(Mx+b).

As a warm up, we study alternation under linear shifts (when M is restricted to be the identity matrix) called the shift invariant alternation (the smallest alternation that can be achieved for the Boolean function f by shifts, denoted by salt(f)). By a result of Lin and Zhang (2017) [7], it follows that bs(f)O(salt(f)2s(f)). Thus, to settle the Sensitivity Conjecture (f,bs(f)poly(s(f))), it suffices to argue that f,salt(f)poly(s(f)). However, we exhibit an explicit family of Boolean functions for which salt(f) is 2Ω(s(f)).

Going further, we use an affine transform A, such that the corresponding function g satisfies bs(f,0n)s(g). We apply this in the setting of quantum communication complexity to prove that for F(x,y)=deff(xy), the bounded error quantum communication complexity of F with prior entanglement, Q1/3(F) is Ω(bs(f,0n)). Our proof builds on ideas from Sherstov (2010) [17] where we use specific properties of the above affine transformation. Using this, we show the following.

(a)

For a fixed prime p and an ϵ, 0<ϵ<1, any Boolean function f that depends on all its inputs with degp(f)(1ϵ)logn must satisfy Q1/3(F)=Ω(nϵ/2logn). Here, degp(f) denotes the degree of the multilinear polynomial over Fp which agrees with f on Boolean inputs.

(b)

For Boolean function f such that there exists primes p and q with degq(f)Ω(degp(f)δ) for δ>2, the deterministic communication complexity - D(F) and Q1/3(F) are polynomially related. In particular, this holds when degp(f)=O(1). Thus, for this class of functions, this answers an open question (see Buhrman and de Wolf (2001) [15]) about the relation between the two measures.

Restricting back to the linear setting, we construct linear transformation A, such that the corresponding function g satisfies, alt(f)2s(g)+1. Using this new relation, we exhibit Boolean functions f (other than the parity function) such that s(f) is Ω(sparsity(f)) where sparsity(f) is the number of non-zero coefficients in the Fourier representation of f. This family of Boolean functions also rule out a potential approach to settle the XOR Log-Rank conjecture via the recently settled Sensitivity conjecture (Hao Huang (2019) [5]).


中文翻译:

灵敏度,仿射变换和量子通信复杂性

在本文中,我们研究布尔函数参数的敏感性(s),块敏感度(s)和交替(alt)经过特殊设计的仿射变换并展示了几种应用。对于功能FF2ñ{-1个1个}一种=中号X+b 对于 中号F2ñ×ñbF2ñ,转换g的结果定义为XF2ñGX=F中号X+b

作为热身,我们研究线性位移(当M被限制为单位矩阵时)下的交替,称为位移不变交替(布尔函数f可以通过位移实现的最小交替,表示为F)。根据Lin和Zhang(2017)[7]的结果,sFØF2sF。因此,要解决敏感性猜想(FsFsF),足以证明 FFsF。但是,我们展示了一个明确的布尔函数族,F2ΩsF

更进一步,我们使用仿射变换A,使得对应的函数g满足sF0ñsG。我们将其应用在量子通信复杂性的设置中,以证明FXÿ=定义FXÿ,先验纠缠F的有界误差量子通信复杂度,1个/3FΩsF0ñ。我们的证明基于Sherstov(2010)[17]的思想,其中我们使用了上述仿射变换的特定属性。使用此,我们显示以下内容。

(一种)

对于固定的素数pε0<ϵ<1个,任何依赖于其所有输入的布尔函数fpF1个-ϵ日志ñ 必须满足 1个/3F=Ωñϵ/2日志ñ。这里,pF 表示上的多元线性多项式的次数 Fp与布尔输入上的f一致。

(b)

对于布尔函数f,使得存在质数pqqFΩpFδ 对于 δ>2,确定性的通信复杂度- dF1个/3F与多项式相关。特别是,当pF=Ø1个。因此,对于此类功能,这回答了有关两个度量之间关系的公开问题(参见Buhrman和de Wolf(2001)[15])。

回到线性设置,我们构造线性变换A,使得对应的函数g满足,altF2sG+1个。使用这个新关系,我们展示布尔函数f(奇偶校验函数除外),使得sFΩ稀疏性F 哪里 稀疏性Ff的傅立叶表示中的非零系数的数量。这个布尔函数族还排除了通过最近解决的敏感度猜想解决XOR Log-Rank猜想的潜在方法(Hao Huang(2019)[5])。
更新日期:2020-06-03
down
wechat
bug