In this paper we investigate a topological characterization of the Runge theorem in the Clifford algebra $ mathbb{R}_3$ via the description of the homology groups of axially symmetric open subsets of the quadratic cone in $mathbb{R}_3$.
In this paper we investigate linear codes with complementary dual (LCD) codes and formally self-dual codes over the ring $R=F_{q}+vF_{q}+v^{2}F_{q}$, where $v^{3}=v$, for $q$ odd. We give conditions on the existence of LCD codes and present construct
ion of formally self-dual codes over $R$. Further, we give bounds on the minimum distance of LCD codes over $F_q$ and extend these to codes over $R$.
For a finite ring $R$, not necessarily commutative, we prove that the category of $text{VIC}(R)$-modules over a left Noetherian ring $mathbf{k}$ is locally Noetherian, generalizing a theorem of the authors that dealt with commutative $R$. As an appli
cation, we prove a very general twisted homology stability for $text{GL}_n(R)$ with $R$ a finite noncommutative ring.
Cartan-Thullen theorem is a basic one in the theory of analytic functions of several complex variables. It states that for any open set $U$ of ${mathbb C}^k$, the following conditions are equivalent: (a) $U$ is a domain of existence, (b) $U$ is a dom
ain of holomorphy and (c) $U$ is holomorphically convex. On the other hand, when $f , (, =(f_1,f_2,cdots,f_n), )$ is a $mathbb C^n$-valued function on an open set $U$ of $mathbb C^{k_1}timesmathbb C^{k_2}timescdotstimesmathbb C^{k_n}$, $f$ is said to be $mathbb C^n$-analytic, if $f$ is complex analytic and for any $i$ and $j$, $i ot=j$ implies $frac{partial f_i}{partial z_j}=0$. Here, $(z_1,z_2,cdots,z_n) in mathbb C^{k_1}timesmathbb C^{k_2}timescdotstimesmathbb C^{k_n}$ holds. We note that a $mathbb C^n$-analytic mapping and a $mathbb C^n$-analytic manifold can be easily defined. In this paper, we show an analogue of Cartan-Thullen theorem for a $mathbb C^n$-analytic function. For $n=1$, it gives Cartan-Thullen theorem itself. Our proof is almost the same as Cartan-Thullen theorem. Thus, our generalization seems to be natural. On the other hand, our result is partial, because we do not answer the following question. That is, does a connected open $mathbb C^n$-holomorphically convex set $U$ exist such that $U$ is not the direct product of any holomorphically convex sets $U_1, U_2, cdots, U_{n-1}$ and $U_n$ ? As a corollary of our generalization, we give the following partial result. If $U$ is convex, then $U$ is the direct product of some holomorphically convex sets. Also, $f$ is said to be $mathbb C^n$-triangular, if $f$ is complex analytic and for any $i$ and $j$, $i<j$ implies $frac{partial f_i}{partial z_j}=0$. Kasuya suggested that a $mathbb C^n$-analytic manifold and a $mathbb C^n$-triangular manifold might, for example, be related to a holomorphic web and a holomorphic foliation.
It has been known for a long time that the fundamental group of the quotient of $RR ^3$ by the Case-Chamberlin continuum is nontrivial. In the present paper we prove that this group is in fact, uncountable.
In this note we study and obtain factorization theorems for colorings of matrices and Grassmannians over $mathbb{R}$ and ${mathbb{C}}$, which can be considered metr