We study the computational complexity of counting the fixed point configurations in certain discrete dynamical systems. We prove that both exact and approximate counting in Sequential and Synchronous Dynamical Systems (SDSs and SyDS, respectrively) is computationally intractable, even when each node is required to update according to a symmetric Boolean ... more >>>

We consider the problem of finding a maximum independent set in a
random graph. The random graph $G$ is modelled as follows. Every
edge is included independently with probability $\frac{d}{n}$, where
$d$ is some sufficiently large constant. Thereafter, for some
constant $\alpha$, a subset $I$ of $\alpha n$ vertices is ... more >>>

We consider the problem of computing the Hamming weight of an n-bit vector using a circuit with gates for GF2 addition and multiplication only. We show the number of multiplications necessary and sufficient to build such a circuit is n - |n| where |n| is the Hamming weight of the ... more >>>