{"title":"高效计算有限类型不变式","authors":"Dror Bar-Natan, Itai Bar-Natan, Iva Halacheva, Nancy Scherich","doi":"arxiv-2408.15942","DOIUrl":null,"url":null,"abstract":"We describe an efficient algorithm to compute finite type invariants of type\n$k$ by first creating, for a given knot $K$ with $n$ crossings, a look-up table\nfor all subdiagrams of $K$ of size $\\lceil \\frac{k}{2}\\rceil$ indexed by dyadic\nintervals in $[0,2n-1]$. Using this algorithm, any such finite type invariant\ncan be computed on an $n$-crossing knot in time $\\sim n^{\\lceil\n\\frac{k}{2}\\rceil}$, a lot faster than the previously best published bound of\n$\\sim n^k$.","PeriodicalId":501271,"journal":{"name":"arXiv - MATH - Geometric Topology","volume":"75 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Computing Finite Type Invariants Efficiently\",\"authors\":\"Dror Bar-Natan, Itai Bar-Natan, Iva Halacheva, Nancy Scherich\",\"doi\":\"arxiv-2408.15942\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We describe an efficient algorithm to compute finite type invariants of type\\n$k$ by first creating, for a given knot $K$ with $n$ crossings, a look-up table\\nfor all subdiagrams of $K$ of size $\\\\lceil \\\\frac{k}{2}\\\\rceil$ indexed by dyadic\\nintervals in $[0,2n-1]$. Using this algorithm, any such finite type invariant\\ncan be computed on an $n$-crossing knot in time $\\\\sim n^{\\\\lceil\\n\\\\frac{k}{2}\\\\rceil}$, a lot faster than the previously best published bound of\\n$\\\\sim n^k$.\",\"PeriodicalId\":501271,\"journal\":{\"name\":\"arXiv - MATH - Geometric Topology\",\"volume\":\"75 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Geometric Topology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.15942\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Geometric Topology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.15942","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
We describe an efficient algorithm to compute finite type invariants of type
$k$ by first creating, for a given knot $K$ with $n$ crossings, a look-up table
for all subdiagrams of $K$ of size $\lceil \frac{k}{2}\rceil$ indexed by dyadic
intervals in $[0,2n-1]$. Using this algorithm, any such finite type invariant
can be computed on an $n$-crossing knot in time $\sim n^{\lceil
\frac{k}{2}\rceil}$, a lot faster than the previously best published bound of
$\sim n^k$.