Skip to main content
Just a user's user avatar
Just a user's user avatar
Just a user's user avatar
Just a user
  • Member for 2 years, 7 months
  • Last seen this week
19 votes
Accepted

What is a Hamel basis?

17 votes

Doubt about the statement of the Fundamental Theorem of Algebra.

12 votes
Accepted

Can you cover $\mathbb R$ with countably many smol sets?

12 votes
Accepted

Example of a PID in which $SL_n \neq E_n$

11 votes
Accepted

why universe is a set?

10 votes
Accepted

Is the set of all algorithms computable?

9 votes

Is $d(A, B) =|(A\Delta B)|$ a metric on all finite subsests?

8 votes

Prove $\det\begin{bmatrix}A & B\\ B & A\end{bmatrix} = \det(A-B)\det(A+B)$, even when $A$ and $B$ are not commutative.

8 votes

Let $G$ be a group and let prime $p\mid \vert G\vert$. Suppose further that $\vert G\vert < p^2 $. Show that $G$ has a normal subgroup of order $p$.

8 votes
Accepted

How to find a basis of a vector space?

7 votes

Word length function on subgroup

7 votes
Accepted

Alternative proof that ring of functions does not contain any nontrivial multiple of the exponential function

6 votes
Accepted

Basic property of ideals

6 votes

How to define the addition and multiplication of p-adic integers as infinite formal sums?

6 votes

Does anyone know a non-trivial surjective multiplicative homomorphism from the $4\times 4$ matrices to the $2 \times 2 $ matrices?

6 votes
Accepted

Unique vector space topology on $F^n$?

6 votes

A problem about a group-like structure

6 votes
Accepted

What are some practical and potential applications of Galois theory in different field of mathematics?

6 votes
Accepted

Let $A$ be ring, then $A[x]$ is formally smooth over $A$.

6 votes
Accepted

How to prove that $\text{Ker}(A)=\text{Ker}(A^2)$ if $A$ is a normal operator?

6 votes

Current research areas of Group Theory

6 votes

How do I handle equations like $f(x)-x = f'(x)$?

6 votes
Accepted

What is the difference between using $(\lambda I - A)$ and $(A - \lambda I)$ when finding eigenvalues and eigenvectors?

6 votes

A norm $\|\cdot\|$ on $\mathbb R^N$ such that $\|x\|^2$ is $C^2$ near $x=0$ is induced by an inner product.

6 votes
Accepted

Is there an easy way for a person to compute the determinant of an arbitrary matrix?

6 votes

Is the subextension of a purely transcendental extension purely transcendental over the base field?

6 votes
Accepted

changing the signs of the harmonic series so that it is still divergent

5 votes

Is $f(x)=x^4+x+2$ irreducible over $\mathbb{Z}_3$?

5 votes
Accepted

Question on non-unital finite dimensional Banach algebras.

5 votes

Orthogonal vectors in complex vector space

1
2 3 4 5
18