Bounding cochordal cover number of graphs via vertex stretching
نویسنده
چکیده مقاله:
It is shown that when a special vertex stretching is applied to a graph, the cochordal cover number of the graph increases exactly by one, as it happens to its induced matching number and (Castelnuovo-Mumford) regularity. As a consequence, it is shown that the induced matching number and cochordal cover number of a special vertex stretching of a graph G are equal provided G is well-covered bipartite or weakly chordal graph.
منابع مشابه
bounding cochordal cover number of graphs via vertex stretching
it is shown that when a special vertex stretching is applied to a graph, the cochordal cover number of the graph increases exactly by one, as it happens to its induced matching number and (castelnuovo-mumford) regularity. as a consequence, it is shown that the induced matching number and cochordal cover number of a special vertex stretching of a graph g are equal provided g is well-covered bipa...
متن کاملThe Graphs of Vertex Cover Six
We provide for the first time a complete list of forbidden minors (obstructions) for the family of graphs with vertex cover 6. This paper shows how to limit both the search space of graphs and improve the efficiency of an obstruction checking algorithm when restricted to k–Vertex Cover graph families. In particular, our upper bounds 2k + 1 (2k + 2) on the maximum number of vertices for connecte...
متن کاملTreedepth Parameterized by Vertex Cover Number
To solve hard graph problems from the parameterized perspective, structural parameters have commonly been used. In particular, vertex cover number is frequently used in this context. In this paper, we study the problem of computing the treedepth of a given graph G. We show that there are an O(τ(G)3) vertex kernel and an O(4τ(G)τ(G)n) time fixed-parameter algorithm for this problem, where τ(G) i...
متن کاملBounding the Number of Plane Graphs
We investigate the number of plane geometric, i.e., straight-line, graphs, a set S of n points in the plane admits. We show that the number of plane graphs is minimized when S is in convex position, and that the same result holds for several relevant subfamilies. In addition we construct a new extremal configuration, the so-called double zig-zag chain. Most noteworthy this example bears Θ∗( √ 7...
متن کاملVertex Cover Approximations on Random Graphs
The vertex cover problem is a classical NP-complete problem for which the best worst-case approximation ratio is 2 − o(1). In this paper, we use a collection of simple graph transformations, each of which guarantees an approximation ratio of 3 2 , to find approximate vertex covers for a large collection of randomly generated graphs. These reductions are extremely fast and even though they, by t...
متن کاملDistributed Vertex Cover in Network Graphs
Vertex cover, a minimal set of nodes to cover all edges in a graph, is an abstraction of coverage problems in sensor networks, transportation networks, etc, and is a well-konwn NP-hard problem. Minimum weighted vertex cover (MWVC) problem asks for further minimizing the cumulative weight of a vertex cover. We present new distributed k-hop algorithms for MWVC problem with theoretical and practic...
متن کاملمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ذخیره در منابع من قبلا به منابع من ذحیره شده{@ msg_add @}
عنوان ژورنال
دوره 42 شماره 3
صفحات 679- 685
تاریخ انتشار 2016-06-01
با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023