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Related papers: Lower Bound on the Redundancy of PIR Codes

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Coding theoretic techniques have been proposed for synchronous Gradient Descent (GD) on multiple servers to mitigate stragglers. These techniques provide the flexibility that the job is complete when any $k$ out of $n$ servers finish their…

Information Theory · Computer Science 2020-05-20 Shanuja Sasi , V. Lalitha , Vaneet Aggarwal , B. Sundar Rajan

Service rate is an important, recently introduced, performance metric associated with distributed coded storage systems. Among other interpretations, it measures the number of users that can be simultaneously served by the storage system.…

Information Theory · Computer Science 2020-01-27 Fatemeh Kazemi , Sascha Kurz , Emina Soljanin

We approach index coding as a special case of rate-distortion with multiple receivers, each with some side information about the source. Specifically, using techniques developed for the rate-distortion problem, we provide two upper bounds…

Information Theory · Computer Science 2015-07-28 Sinem Unal , Aaron B. Wagner

In the conventional robust $T$-colluding private information retrieval (PIR) system, the user needs to retrieve one of the possible messages while keeping the identity of the requested message private from any $T$ colluding servers.…

Information Theory · Computer Science 2021-12-13 Ruida Zhou , Chao Tian , Hua Sun , James Plank

According to a classical result of Spencer, Szemer\'edi, and Trotter (1984), the maximum number of times the unit distance can occur among $n$ points in the plane is $O(n^{4/3})$. This is far from Erd\H{o}s's lower bound, $n^{1+O(1/\log\log…

Combinatorics · Mathematics 2025-07-22 János Pach , Orit E. Raz , József Solymosi

A recent article introduced a hierarchy of quantities called $k$-fidelities that approximate the quantum process fidelity with increasing accuracy. The lowest approximation in this hiearchy is the $0$-fidelity. The authors gave a protocol…

Quantum Physics · Physics 2021-09-21 Karl Mayer

For the discrete memoryless sources with a countably infinite alphabet, we prove that for any positive integer $k$, there exists a corresponding probability interval such that if the largest symbol probability $p_{1}$ falls in this…

Information Theory · Computer Science 2026-04-21 Hongyang Liu , Wei Yan

In this paper we estimate the fidelity of stabilizer and CSS codes. First, we derive a lower bound on the fidelity of a stabilizer code via its quantum enumerator. Next, we find the average quantum enumerators of the ensembles of finite…

Quantum Physics · Physics 2017-02-10 Alexei Ashikhmin

We consider the problem of designing a Private Information Retrieval (PIR) scheme on $m$ files replicated on $k$ servers that can collude or, even worse, can return incorrect answers. Our goal is to correctly retrieve a specific message…

Information Theory · Computer Science 2023-05-08 Stanislav Kruglik , Son Hoang Dau , Han Mao Kiah , Huaxiong Wang

The repetition threshold is the smallest real number $\alpha$ such that there exists an infinite word over a $k$-letter alphabet that avoids repetition of exponent strictly greater than $\alpha$. This notion can be generalized to graph…

Discrete Mathematics · Computer Science 2018-06-29 Borut Lužar , Pascal Ochem , Alexandre Pinlou

We study the time complexity of the discrete $k$-center problem and related (exact) geometric set cover problems when $k$ or the size of the cover is small. We obtain a plethora of new results: - We give the first subquadratic algorithm for…

Computational Geometry · Computer Science 2023-05-04 Timothy M. Chan , Qizheng He , Yuancheng Yu

Assuming iterative decoding for binary erasure channels (BECs), a novel tree-based technique for upper bounding the bit error rates (BERs) of arbitrary, finite low-density parity-check (LDPC) codes is provided and the resulting bound can be…

Information Theory · Computer Science 2007-07-13 Chih-Chun Wang , Sanjeev R. Kulkarni , H. Vincent Poor

We analyse the convergence to equilibrium of the Bernoulli--Laplace urn model: initially, one urn contains $k$ red balls and a second $n-k$ blue balls; in each step, a pair of balls is chosen uniform and their locations are switched. Cutoff…

Probability · Mathematics 2024-09-13 Sam Olesker-Taylor , Dominik Schmid

Private information retrieval (PIR) is the problem of retrieving as efficiently as possible, one out of $K$ messages from $N$ non-communicating replicated databases (each holds all $K$ messages) while keeping the identity of the desired…

Information Theory · Computer Science 2016-05-03 Hua Sun , Syed A. Jafar

Given a finite, simple graph $G$, the $k$-component order edge connectivity of $G$ is the minimum number of edges whose removal results in a subgraph for which every component has order at most $k-1$. In general, determining the…

Combinatorics · Mathematics 2023-10-10 Michael Yatauro

In this article, We introduce a condition that is both necessary and sufficient for a linear code to achieve minimality when analyzed over the rings $\mathbb{Z}_{n}$.The fundamental inquiry in minimal linear codes is the existence of a…

Information Theory · Computer Science 2025-11-24 Biplab Chatterjee , Ratnesh Kumar Mishra

The time-optimal $k$-server problem minimizes the time spent serving all requests instead of the distances traveled. We give a lower bound of $2k-1$ on the competitive ratio of any deterministic online algorithm for this problem, which…

Data Structures and Algorithms · Computer Science 2025-03-10 Fabian Frei , Dennis Komm , Moritz Stocker , Philip Whittington

Gap Hamming Distance is a well-studied problem in communication complexity, in which Alice and Bob have to decide whether the Hamming distance between their respective n-bit inputs is less than n/2-sqrt(n) or greater than n/2+sqrt(n). We…

Computational Complexity · Computer Science 2009-12-31 Joshua Brody , Amit Chakrabarti , Oded Regev , Thomas Vidick , Ronald de Wolf

We consider the partial data inverse boundary problem for the Schr\"odinger operator at a frequency $k>0$ on a bounded domain in $\mathbb{R}^n$, $n\ge 3$, with impedance boundary conditions. Assuming that the potential is known in a…

Analysis of PDEs · Mathematics 2019-07-23 Katya Krupchyk , Gunther Uhlmann

After the optimal parameters of additive quaternary codes of dimension $k\le 3$ have been determined there is some recent activity to settle the next case of dimension $k=3.5$. Here we complete dimension $k=3.5$ and $k=4$. We also solve the…

Combinatorics · Mathematics 2026-05-11 Sascha Kurz