Questions tagged [dc.parallel-comp]
Theoretical questions in Parallel Computing
12
questions
21
votes
2answers
727 views
What is the big version of NC?
$\mathsf{NC}$ captures the idea of efficiently parallelizable, and one interpretation of it is problems that are solvable in time $O(\log^c n)$ using $O(n^k)$ parallel processors for some constants $c$...
19
votes
1answer
765 views
Is solving systems of equations modulo $k$ in $\mathsf{coMod}_k\mathsf L$ for $k$ composite?
I'm interested in the complexity of solving linear equations modulo k, for arbitrary k (and with a special interest in prime powers), specifically:
Problem. For a given system of $m$ linear ...
13
votes
3answers
839 views
Parallel algorithms for directed st-connectivity
Chong, Han and Lam showed that undirected st-connectivity can be solved on the EREW PRAM in $O({\log}n)$ time with $O(m+n)$ processors. What is the best known parallel algorithm for directed st-...
30
votes
10answers
1k views
Current parallel models for computation
The 1980's gave rise to both the PRAM and the BSP models of parallel computation. It seems that both model's heyday were during the late 80s and early 90s.
Are these areas still active in terms of ...
17
votes
2answers
784 views
Status on circuit lower bounds for polylog-bounded depth circuits
Bounded depth circuit complexity is one of the main areas of research within circuit complexity theory. This topic has origins in results like "the parity function is not in $AC^{0}$" and "the mod $p$ ...
14
votes
1answer
396 views
Problems in NC not known to lie in NC2
Are there interesting problems that are in $\mathsf{NC}$ but not known to be in $\mathsf{NC^{2}}$? In the paper 'A Taxonomy of Problems With Fast Parallel Algorithms', Cook mentions that MIS was known ...
14
votes
1answer
707 views
Is there a quantum NC algorithm for computing GCD?
From the comments on one of my questions on MathOverflow
I get the feeling that the question regarding GCD being in $\mathsf{NC}$ vs. $\mathsf{P}$ is akin to the question regarding Integer ...
4
votes
1answer
380 views
Modern distributed computing book
Lynch's Distributed Algorithms book is a classic but it is from 1996 and rather out of date. Are there any recent distributed computing books that can be used as textbooks for a graduate distributed ...
13
votes
2answers
371 views
When a process spawns another process
My background is in complexity theory/logic (where there is just one process most of the time), and in distributed computing (where there are $n$ processes, and one or more might fail over time). ...
11
votes
1answer
234 views
To what extent, computational ability for hard tasks helps in solving easy tasks
In short, the question is: to what extent, computational ability for hard tasks really helps you in solving easy tasks. (There could be various ways to make this question interesting and non-trivial, ...
10
votes
0answers
107 views
Problems in $\mathsf{NC^{2}}$ that are not known to be in $\mathsf{AC^{1}}$ or $\mathsf{DET}$
Do we know of any problems in $\mathsf{NC^{2}}$ that are not known to be in $\mathsf{AC^{1}}$ or $\mathsf{DET}$?
Context: based on Josh's answer to this question, it could be possible that all ...
5
votes
1answer
180 views
Confusion about a formal definition of PRAM consistency
I am reading the paper "Consistency in Non-Transactional Distributed Storage Systems" by Paolo Viotti and Marko Vukolić. The authors provide a comprehensive survey of various consistency semantics ...
