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Isaev Roman

Publications and source records attributed to Isaev Roman.

2 recordsLinked to original sources

The flexibility of $m$-suspensions constructed via a local slice

We refer to the variety $\operatorname{Susp}(X, f, k_1, \dots, k_m) = \mathbb{V}(y_1^{k_1} \dots y_m^{k_m} - f(x)) \subset X \times \mathbb{A}^m$ as an $m$-suspension over affine variety $X$, constructed via a local slice $f(x) \in \mathbb{K}[X]$, if there exists a locally nilpotent derivation $\delta$ on $X$ such that $\delta (f) \neq 0, \delta^2 (f) = 0$. In this paper, we determine the sufficient conditions under which such a variety is generically flexible and those under which it is flexible. Furthermore, for a flexible $X$ we propose a construction of a local slice $f$ that guarantees the flexibility of the suspension $\operatorname{Susp}(X, f, 1, k_2, \dots, k_m)$.

math.AG

The invariants of n-dimensional Rubik's Cube

It is well known that Rubik's cube has a set of group invariants. These values do not change if any layer was rotated, but they can change in case if some of the cubes were removed from the puzzle, mixed up and returned back. In this paper, we generalize the puzzle to the case of an arbitrary dimension after which we describe all the invariants.

math.GR