**4**

votes

**0**answers

559 views

### Path connected set of matrices?

Consider the collection of $n$ by $n$ matrices
$$S=\{ A: A_{ij}\le0,\quad (-1)^{c_i}\det A(P_i;Q_i)<0 \quad \text{for} \quad i=1,\ldots, k\}$$
where $c_i\in \{0,1\}$, $P_i$ and $Q_i$ are disjoint ...

**2**

votes

**0**answers

57 views

### On low rank $0/1$ real matrices with one connected component

Let $M$ be an $n\times n$ $0-1$ matrix of real rank $r$.
Moreover assume every row of $M$ is distinct and every column of $M$ is distinct. Such a matrix cannot be bigger than $2^r\times 2^r$.
As in ...

**2**

votes

**0**answers

74 views

### Number of self avoiding paths which are not ``tie together''

Consider the lattice $\mathbb{Z}^d$. Let $A_{n}$ be the set of returning self-avoiding paths (from $0$ to $0$) having length $n$. For any path $\omega \in A_{n}$, let $f(\omega)$ be the number of ...

**1**

vote

**0**answers

66 views

### Analogue of a path-connected subspace in the context of point processes

Given a set of points $S$ in some metric space, a pair of points $x, x'$ will be termed $\epsilon$-connected if they are connected by a series of points $x_1, \ldots, x_m \in S$ such that $d(x, x_1)$, ...

**0**

votes

**0**answers

172 views

### When is $\{ x \ge 0 | f(x) \le 0\}$ path-connected?

I'm trying to determine the conditions on $f : \mathbb{R}^n_{\ge 0} \to \mathbb{R^n}$ under which $\{ x \ge 0 | f(x) \le 0 \}$ is path-connected. We can assume that $f$ is continuous and concave.
...