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Does randomness help depth?

Suppose we have a $RNC^i$ or $BPNC^i$ algorithm for a problem, is it suspected that the problem has an $NC^i$ algorithm or just an $NC^j$ algorithm for some $j\geq i$? Is there any evidence for ...
Turbo's user avatar
  • 13.3k
11 votes
2 answers
893 views

Randomized algorithms not based on Schwartz-Zippel

Are there any problems that are known to be in a randomized complexity class (e.g. RNC, ZPP, RP, BPP, or even PP), but not in any lower non-randomized class (e.g. NC, P, NP), and whose membership in ...
Shaull's user avatar
  • 5,636
3 votes
1 answer
468 views

Can the halting problem be solved probabilistically? [closed]

Let $H$ be the halting oracle, meaning that $H$ is a function on pairs of strings such that $H(P,X) = 1$ iff $P$ halts on $X$. A probabilistic program is a program that has (oracle) access to a random ...
user21820's user avatar
  • 134
1 vote
1 answer
126 views

Efficient randomness reduction using k-wise independence

Consider a randomized algorithm with runtime $n$, which succeeds with high probability. The algorithm uses $O(n)$ uniformly random bits. Now it is given that we can replace these uniformly random ...
smapers's user avatar
  • 849
10 votes
1 answer
293 views

Uniform derandomisation of circuit complexity classes

Let $\mathcal{C}$ be a complexity class and $\textrm{BP-}\mathcal{C}$ be the randomized counterpart of $\mathcal{C}$ defined in the same way as $\textrm{BPP}$ is defined with respect to $\textrm{P}$. ...
C.P.'s user avatar
  • 1,002
14 votes
1 answer
471 views

Adleman's theorem over infinite semirings?

Adleman has shown in 1978 that $\mathrm{BPP}\subseteq \mathrm{P/poly}$: if a boolean function $f$ of $n$ variables can be computed by a probabilistic boolean circuit of size $M$, then $f$ can be also ...
Stasys's user avatar
  • 6,795
16 votes
5 answers
2k views

Examples of successful derandomization from BPP to P

What are some major examples of successful derandomization or at least progress in showing concrete evidence towards $P=BPP$ goal (not the hardness randomness connection)? The only example that comes ...
user avatar
5 votes
1 answer
360 views

Smallest $f(n)$ such that $P/f(n) = BPP/f(n)$?

It is well-known that $\mathsf{P/poly}(n) = \mathsf{BPP/poly}(n)$. It is a major open problem to prove the conjecture $\mathsf{P} = \mathsf{BPP}$. $\mathsf{P} = \mathsf{BPP}$ implies $\mathsf{P}/f(n) ...
Ryan Dougherty's user avatar
-1 votes
1 answer
251 views

Is there a randomized complexity class analogous to $\mathsf{P/Poly}$?

$\mathsf{P/Poly}$ captures those problems that could be solved in polynomial time given some precomputed polynomial number of constants. Is there an analogous complexity class in randomized world ...
Turbo's user avatar
  • 13.3k
4 votes
0 answers
191 views

Randomized Parallel Algorithm for Maximal Independent Set

There are a couple of randomized parallel algorithms for the maximal independent set problem, e.g. A Simple Parallel Algorithm for the Maximal Independent Set Problem, A fast and simple randomized ...
Marc Bury's user avatar
  • 1,338
4 votes
0 answers
164 views

Concentration Bounds for Dependent Rounding

Consider the following random process which is defined on $n$ numbers $0\leq x_1,\ldots,x_n\leq 1$: At each step, pick an arbitrary number, say $x_i$. Then randomly (and independently) change its ...
afshi7n's user avatar
  • 271
7 votes
0 answers
638 views

Narrowing the gap between BPP and RP

We do not know yet whether the 2-sided error of $BPP$ allows more computing power than the one sided error of $RP$. In view of derandomization results, the conjectured answer is no, since both classes ...
Andras Farago's user avatar
39 votes
9 answers
4k views

Efficient and simple randomized algorithms where determinism is difficult

I often hear that for many problems we know very elegant randomized algorithms, but no, or only more complicated, deterministic solutions. However, I only know a few examples for this. Most ...
adrianN's user avatar
  • 877
10 votes
1 answer
304 views

What are some results on algorithms that estimate polynomials over a given set of points?

There seem to be many randomized algorithms for polynomial identity testing, checking whether or not a given polynomial is zero. Are there any results of algorithms that do some sort of estimation of ...
Shravas Rao's user avatar
18 votes
3 answers
839 views

Does randomness buy us anything inside P?

Let $\mathsf{BPTIME}(f(n))$ be the class of the decision problems having a bounded two-sided error randomized algorithm running in time $O(f(n))$. Do we know of any problem $Q \in \mathsf{P}$ such ...
aelguindy's user avatar
  • 951
19 votes
3 answers
703 views

Running a BPP algorithm with a half-random, half-adversarial string

Consider the following model: an n-bit string r=r1...rn is chosen uniformly at random. Next, each index i∈{1,...,n} is put into a set A with independent probability 1/2. Finally, an adversary ...
Scott Aaronson's user avatar
4 votes
1 answer
276 views

What's the strict definition of random coins in streaming algorithm?

I have a very basic question about random bits in streaming. How could a streaming algorithm use them? Can the algorithm use the same random bit at the start of the execution and look at it again ...
Wei Yu's user avatar
  • 331
18 votes
2 answers
2k views

Beginner's Guide to Derandomization

I found the book Pairwise Independence and Derandomization on the subject, but it's more research-oriented than tutorial oriented. I'm new to the subject of "Derandomization," and as such, I wanted ...
Sadeq Dousti's user avatar
  • 16.6k
28 votes
4 answers
2k views

What specific evidence is there for P = RP?

RP is the class of problems decidable by a nondeterministic Turing machine that terminates in polynomial time, but that is also allowed one-sided error. P is the usual class of problems decidable by ...
András Salamon's user avatar