# Algebra

## 1812 Submissions

[2] **viXra:1812.0203 [pdf]**
*replaced on 2018-12-12 10:43:42*

### Review on Rationality Problems of Algebraic K-Tori

**Authors:** Youngjin Bae

**Comments:** 12 Pages.

Rationality problems of algebraic k-tori are closely related to rationality problems of the invariant field, also known as Noether's Problem. We describe how a function field of algebraic k-tori can be identified as an invariant field under a group action and that a k-tori is rational if and only if its function field is rational over k. We also introduce character group of k-tori and numerical approach to determine rationality of k-tori.

**Category:** Algebra

[1] **viXra:1812.0039 [pdf]**
*submitted on 2018-12-02 06:25:19*

### Refutation of Kent Algebras on Rough Set Concept Analysis

**Authors:** Colin James III

**Comments:** 1 Page. © Copyright 2018 by Colin James III All rights reserved. Respond to the author by email at: info@ersatz-systems dot com.

We use modal logic to evaluate definitions for Kent algebras, as presented for rough set concept analysis. Some definitions are not tautologous, hence refuting Kent algebras on rough sets.

**Category:** Algebra