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Non-Archimedean and p-adic Functional Welch Bounds

Number Theory 2022-09-15 v1 Algebraic Geometry Functional Analysis Spectral Theory

Abstract

We prove the non-Archimedean (resp. p-adic) Banach space version of non-Archimedean (resp. p-adic) Welch bounds recently obtained by M. Krishna. More precisely, we prove following results. 1. Let K\mathbb{K} be a non-Archimedean (complete) valued field satisfying j=1nλj2=max1jnλj2\left|\sum_{j=1}^{n}\lambda_j^2\right|=\max_{1\leq j \leq n}|\lambda_j|^2 for all λjK,1jn \lambda_j \in \mathbb{K}, 1\leq j \leq n, for all nN.n \in \mathbb{N}. Let X\mathcal{X} be a dd-dimensional non-Archimedean Banach space over K\mathbb{K}. If {τj}j=1n\{\tau_j\}_{j=1}^n is any collection in X\mathcal{X} and {fj}j=1n\{f_j\}_{j=1}^n is any collection in X\mathcal{X}^* (dual of X\mathcal{X}) satisfying fj(τj)=1f_j(\tau_j) =1 for all 1jn1\leq j \leq n and the operator Sf,τ:Symm(X)xj=1nfjm(x)τjmSymm(X)S_{f, \tau} : \text{Sym}^m(\mathcal{X})\ni x \mapsto \sum_{j=1}^nf_j^{\otimes m}(x)\tau_j^{\otimes m} \in \text{Sym}^m(\mathcal{X}), is diagonalizable, then \begin{align} \text{(Non-Archimedean Functional Welch Bounds)} \quad \max_{1\leq j,k \leq n, j \neq k}\{|n|, |f_j(\tau_k)f_k(\tau_j)|^{m} \}\geq \frac{|n|^2}{\left|{d+m-1 \choose m}\right| }. \end{align} 2. For a prime pp, let Qp\mathbb{Q}_p be the p-adic number field. Let X\mathcal{X} be a dd-dimensional p-adic Banach space over Qp\mathbb{Q}_p. If {τj}j=1n\{\tau_j\}_{j=1}^n is any collection in X\mathcal{X} and {fj}j=1n\{f_j\}_{j=1}^n is any collection in X\mathcal{X}^* (dual of X\mathcal{X}) satisfying fj(τj)=1f_j(\tau_j) =1 for all 1jn1\leq j \leq n and there exists bQpb \in \mathbb{Q}_p such that j=1nfjm(x)τjm=bx \sum_{j=1}^{n}f_j^{\otimes m}(x) \tau_j^{\otimes m} =bx for all xSymm(X), x \in \text{Sym}^m(\mathcal{X}), then \begin{align} \text{(p-adic Functional Welch Bounds)} \quad \max_{1\leq j,k \leq n, j \neq k}\{|n|, |f_j(\tau_k)f_k(\tau_j)|^{m} \}\geq \frac{|n|^2}{\left|{d+m-1 \choose m}\right| }. \end{align} We formulate non-Archimedean functional and p-adic functional Zauner conjectures.

Keywords

Cite

@article{arxiv.2209.06769,
  title  = {Non-Archimedean and p-adic Functional Welch Bounds},
  author = {K. Mahesh Krishna},
  journal= {arXiv preprint arXiv:2209.06769},
  year   = {2022}
}

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R2 v1 2026-06-28T01:18:10.547Z