Fixed-Parameter Tractability and Completeness IV: On Completeness for W[P] and PSPACE Analogues
نویسندگان
چکیده
We describe new results in parameterized complexity theory. In particular, we prove a number of concrete hardness results for W [P ], the top level of the hardness hierarchy introduced by Downey and Fellows in a series of earlier papers. We also study the parameterized complexity of analogues of PSPACE via certain natural problems concerning k-move games. Finally, we examine several aspects of the structural complexity of W [P ] and related classes. For instance, we show that W [P ] can be characterized in terms of the DTIME(2o(n))
منابع مشابه
Fixed-Parameter Tractability and Completeness II: On Completeness for W[1]
For many fixed-parameter problems that are trivially solvable in polynomial-time, such as kDOMINATING SET, essentially no better algorithm is presently known than the one which tries all possible solutions. Other problems, such as FEEDBACK VERTEX SET, exhibit fixed-parameter tractability: for each fixed k the problem is solvable in time bounded by a polynomial of degree c, where c is a constant...
متن کاملFixed-Parameter Tractability and Completeness I: Basic Results
For many fixed-parameter problems that are trivially soluable in polynomial time, such as (k-)DOMINATING SET, essentially no better algorithm is presently known than the one which tries all possible solutions. Other problems, such as (k-)FEEDBACK VERTEX SET, exhibit fixed-parameter tractability: for each fixed k the problem is soluable in time bounded by a polynomial of degree c, where c is a c...
متن کاملFixed-Parameter Tractability and Completeness III: Some Structural Aspects of the W Hierarchy
We analyse basic structural aspects of the reducibilities we use to describe fixed parameter tractability and intractability, in the model we introduced in earlier papers in this series. Results include separation and density, the latter for the strongest reducibility.
متن کاملSuzuki-type fixed point theorems for generalized contractive mappings that characterize metric completeness
Inspired by the work of Suzuki in [T. Suzuki, A generalized Banach contraction principle that characterizes metric completeness, Proc. Amer. Math. Soc. 136 (2008), 1861--1869], we prove a fixed point theorem for contractive mappings that generalizes a theorem of Geraghty in [M.A. Geraghty, On contractive mappings, Proc. Amer. Math. Soc., 40 (1973), 604--608]an...
متن کاملON COMPACTNESS AND G-COMPLETENESS IN FUZZY METRIC SPACES
In [Fuzzy Sets and Systems 27 (1988) 385-389], M. Grabiec in- troduced a notion of completeness for fuzzy metric spaces (in the sense of Kramosil and Michalek) that successfully used to obtain a fuzzy version of Ba- nachs contraction principle. According to the classical case, one can expect that a compact fuzzy metric space be complete in Grabiecs sense. We show here that this is not the case,...
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:
- Ann. Pure Appl. Logic
دوره 73 شماره
صفحات -
تاریخ انتشار 1995