Wheel-Free Deletion Is W[2]-Hard
نویسنده
چکیده
We show that the two problems of deciding whether k vertices or k edges can be deleted from a graph to obtain a wheel-free graph is W [2]-hard. This immediately implies that deciding whether k edges can be added to obtain a graph that contains no complement of a wheel as an induced subgraph isW [2]-hard, thereby resolving an open problem of Heggernes et. al. [7] (STOC07) who asks whether there is a polynomial time recognizible hereditary graph class Π with the property that computing the minimum Π-completion is W [t]-hard for some t.
منابع مشابه
On the Hardness of Eliminating Small Induced Subgraphs by Contracting Edges
Graph modification problems such as vertex deletion, edge deletion or edge contractions are a fundamental class of optimization problems. Recently, the parameterized complexity of the contractibility problem has been pursued for various specific classes of graphs. Usually, several graph modification questions of the deletion variety can be seen to be FPT if the graph class we want to delete int...
متن کاملFrom Crossing-Free Graphs on Wheel Sets to Embracing Simplices and Polytopes with Few Vertices
A set P = H ∪ {w} of n + 1 points in the plane is called a wheel set if all points but w are extreme. We show that for the purpose of counting crossing-free geometric graphs on P , it suffices to know the so-called frequency vector of P . While there are roughly 2 distinct order types that correspond to wheel sets, the number of frequency vectors is only about 2n/2. We give simple formulas in t...
متن کاملPhysico-Mechanical Analysis of Free Ethylcellulose Films Plasticized with Incremental Weight Percents of Dibutyl Sebacate
This research was conducted to investigate the physico-mechanical characteris-tics of the ethylcellulose-based coating membranes plasticized with different weight percents of dibutyl sebacate. In this experiment, free thin polymer sheetings of the sample formulations, by incorporating incremental weight percents of the plasticizer, were prepared employing a revised casting method of dela...
متن کاملThrshold Radius for Restraining Rail
This paper deals with the threshold radius that warrants the use of single restraining rail for transit and railroads. Different railways use different threshold radius from 91m to 365m to provide restraining rail. These threshold figures are probably experience driven choices. The need for restraining rail may be related to a so-called derailment alarm coefficient of 1.2 sustained over 2m leng...
متن کاملTwo wheel-like polytungstates obtained by incorporation of two {Cu4} clusters and two molybdenum centers in the {W48} wheel.
Two new {P(8)W(48)} wheel-based compounds, Na(12)Li(16){[Cu(H(2)O)](2)[Cu(4)(OH)(4)(H(2)O)(8)](2)P(8)W(48)O(184)}·55H(2)O (1), and K(4)Na(24)Li(10){(MoO(2))(2)(P(8)W(48)O(184))}·61H(2)O (2) have been synthesized by a conventional aqueous solution method, and characterized by UV, IR, TG analysis, XPRD, (31)P NMR, XPS, single-crystal X-ray diffraction analyses, magnetic study and electrochemistry...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008