IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-13 DOI: 10.1142/s2010324723500224

M. Mebrek, B. Medjahed, M. Zemouli, Benabdellah Benyamina, Mohamed Berber, Djillali Benziadi, S. Amrani

引用次数: 0

The XZ model in the Mean-Field Approximation with Exponential Pauli Spin Matrices 指数泡利自旋矩阵平均场近似中的XZ模型

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-13 DOI: 10.1142/s2010324723500212

E. Albayrak

引用次数: 0

Prolonging the Qubits Entanglement via Local Surface Plasmon Modes 利用局域表面等离子体模延长量子纠缠

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-07 DOI: 10.1142/s2010324723400179

Chia-Yi Ju, Wan-Yu Liu, Shuo-Yen Chen, Guang-Yin Chen

引用次数: 0

Rotational symmetry breaking enhanced frequency comb of NiFe vortex in a square disk 方形圆盘中NiFe涡旋的旋转对称破缺增强频率梳

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-07 DOI: 10.1142/s2010324723500200

Shizhu Qiao

引用次数: 0

Quantum computing principles and applications 量子计算原理及应用

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-07 DOI: 10.1142/s2010324723300013

Guanru Feng, Dawei Lu, Jun Li, T. Xin, B. Zeng

引用次数: 0

Approximation Algorithms for Directed Weighted Spanners 有向加权扳手的近似算法

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-06 DOI: 10.48550/arXiv.2307.02774

Elena Grigorescu, Nithish Kumar, Young-San Lin

{"title":"Approximation Algorithms for Directed Weighted Spanners","authors":"Elena Grigorescu, Nithish Kumar, Young-San Lin","doi":"10.48550/arXiv.2307.02774","DOIUrl":"https://doi.org/10.48550/arXiv.2307.02774","url":null,"abstract":"In the pairwise weighted spanner problem, the input consists of an $n$-vertex-directed graph, where each edge is assigned a cost and a length. Given $k$ vertex pairs and a distance constraint for each pair, the goal is to find a minimum-cost subgraph in which the distance constraints are satisfied. This formulation captures many well-studied connectivity problems, including spanners, distance preservers, and Steiner forests. In the offline setting, we show: 1. An $tilde{O}(n^{4/5 + epsilon})$-approximation algorithm for pairwise weighted spanners. When the edges have unit costs and lengths, the best previous algorithm gives an $tilde{O}(n^{3/5 + epsilon})$-approximation, due to Chlamt'av{c}, Dinitz, Kortsarz, and Laekhanukit (TALG, 2020). 2. An $tilde{O}(n^{1/2+epsilon})$-approximation algorithm for all-pair weighted distance preservers. When the edges have unit costs and arbitrary lengths, the best previous algorithm gives an $tilde{O}(n^{1/2})$-approximation for all-pair spanners, due to Berman, Bhattacharyya, Makarychev, Raskhodnikova, and Yaroslavtsev (Information and Computation, 2013). In the online setting, we show: 1. An $tilde{O}(k^{1/2 + epsilon})$-competitive algorithm for pairwise weighted spanners. The state-of-the-art results are $tilde{O}(n^{4/5})$-competitive when edges have unit costs and arbitrary lengths, and $min{tilde{O}(k^{1/2 + epsilon}), tilde{O}(n^{2/3 + epsilon})}$-competitive when edges have unit costs and lengths, due to Grigorescu, Lin, and Quanrud (APPROX, 2021). 2. An $tilde{O}(k^{epsilon})$-competitive algorithm for single-source weighted spanners. Without distance constraints, this problem is equivalent to the directed Steiner tree problem. The best previous algorithm for online directed Steiner trees is $tilde{O}(k^{epsilon})$-competitive, due to Chakrabarty, Ene, Krishnaswamy, and Panigrahi (SICOMP, 2018).","PeriodicalId":54319,"journal":{"name":"Spin","volume":"463 1","pages":"8:1-8:23"},"PeriodicalIF":1.8,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81738430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Approximation Algorithm for the Exact Matching Problem in Bipartite Graphs 二部图精确匹配问题的近似算法

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-05 DOI: 10.48550/arXiv.2307.02205

Anita Dürr, Nicolas El Maalouly, Lasse Wulf

{"title":"An Approximation Algorithm for the Exact Matching Problem in Bipartite Graphs","authors":"Anita Dürr, Nicolas El Maalouly, Lasse Wulf","doi":"10.48550/arXiv.2307.02205","DOIUrl":"https://doi.org/10.48550/arXiv.2307.02205","url":null,"abstract":"In 1982 Papadimitriou and Yannakakis introduced the Exact Matching problem, in which given a red and blue edge-colored graph $G$ and an integer $k$ one has to decide whether there exists a perfect matching in $G$ with exactly $k$ red edges. Even though a randomized polynomial-time algorithm for this problem was quickly found a few years later, it is still unknown today whether a deterministic polynomial-time algorithm exists. This makes the Exact Matching problem an important candidate to test the RP=P hypothesis. In this paper we focus on approximating Exact Matching. While there exists a simple algorithm that computes in deterministic polynomial-time an almost perfect matching with exactly $k$ red edges, not a lot of work focuses on computing perfect matchings with almost $k$ red edges. In fact such an algorithm for bipartite graphs running in deterministic polynomial-time was published only recently (STACS'23). It outputs a perfect matching with $k'$ red edges with the guarantee that $0.5k leq k' leq 1.5k$. In the present paper we aim at approximating the number of red edges without exceeding the limit of $k$ red edges. We construct a deterministic polynomial-time algorithm, which on bipartite graphs computes a perfect matching with $k'$ red edges such that $k/3 leq k' leq k$.","PeriodicalId":54319,"journal":{"name":"Spin","volume":"92 1","pages":"18:1-18:21"},"PeriodicalIF":1.8,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74646277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rapid mixing of global Markov chains via spectral independence: the unbounded degree case 通过谱无关的全局马尔可夫链的快速混合:无界度情况

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-07-02 DOI: 10.48550/arXiv.2307.00683

Antonio Blanca, Xusheng Zhang

{"title":"Rapid mixing of global Markov chains via spectral independence: the unbounded degree case","authors":"Antonio Blanca, Xusheng Zhang","doi":"10.48550/arXiv.2307.00683","DOIUrl":"https://doi.org/10.48550/arXiv.2307.00683","url":null,"abstract":"We consider spin systems on general $n$-vertex graphs of unbounded degree and explore the effects of spectral independence on the rate of convergence to equilibrium of global Markov chains. Spectral independence is a novel way of quantifying the decay of correlations in spin system models, which has significantly advanced the study of Markov chains for spin systems. We prove that whenever spectral independence holds, the popular Swendsen--Wang dynamics for the $q$-state ferromagnetic Potts model on graphs of maximum degree $Delta$, where $Delta$ is allowed to grow with $n$, converges in $O((Delta log n)^c)$ steps where $c>0$ is a constant independent of $Delta$ and $n$. We also show a similar mixing time bound for the block dynamics of general spin systems, again assuming that spectral independence holds. Finally, for monotone spin systems such as the Ising model and the hardcore model on bipartite graphs, we show that spectral independence implies that the mixing time of the systematic scan dynamics is $O(Delta^c log n)$ for a constant $c>0$ independent of $Delta$ and $n$. Systematic scan dynamics are widely popular but are notoriously difficult to analyze. Our result implies optimal $O(log n)$ mixing time bounds for any systematic scan dynamics of the ferromagnetic Ising model on general graphs up to the tree uniqueness threshold. Our main technical contribution is an improved factorization of the entropy functional: this is the common starting point for all our proofs. Specifically, we establish the so-called $k$-partite factorization of entropy with a constant that depends polynomially on the maximum degree of the graph.","PeriodicalId":54319,"journal":{"name":"Spin","volume":"20 1","pages":"53:1-53:19"},"PeriodicalIF":1.8,"publicationDate":"2023-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82400589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Energy and Quality Efficient MTJ/FinFET Approximate 5:2 Compressor for Image Processing Applications 用于图像处理的高效节能MTJ/FinFET近似5:2压缩器

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-06-19 DOI: 10.1142/s2010324723500194

Jalil Mazloum, Behrang Hadian Siahkal-Mahalle

引用次数: 0

Low Power and Fully Non-Volatile Full-Adder based on STT-SHE-MRAM 基于STT-SHE-MRAM的低功耗全非易失性全加器

IF 1.8 4区物理与天体物理

Spin Pub Date : 2023-06-15 DOI: 10.1142/s2010324723500182

Morteza Adelkhani, M. Aminian

引用次数: 0

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