User NazimJ

11 votes

2 answers

2k views

Proof that there exist only 17 Wallpaper Groups (Tilings of the plane)

asked Mar 13, 2019 at 16:31

4 votes

1 answer

249 views

When is the product of closed sets closed in the product topology?

asked Mar 19, 2019 at 21:52

4 votes

0 answers

630 views

Soft Question: Textbook for first graduate course in Functional Analysis

asked Aug 12, 2019 at 16:24

4 votes

3 answers

121 views

Combinatoric meaning to $1+2+\dots+n=\frac{n(n+1)}{2}= {n+1 \choose 2}$ [duplicate]

asked Sep 17, 2020 at 14:41

3 votes

2 answers

331 views

Integral of a function with respect to the measure $\nu(A)=\int_{A}fd\mu$

asked Oct 19, 2018 at 17:54

2 votes

1 answer

377 views

Prove that the measure of the image of G-delta set, $m(f(G))$, is the integral of the derivative, $\int_{G}f^{'} dm$

asked Nov 5, 2018 at 17:35

2 votes

4 answers

2k views

Find the complex roots of this quartic polynomial

asked Mar 6, 2018 at 13:06

2 votes

4 answers

699 views

Intuition behind definition of Connected Space in Topology

asked Jan 28, 2019 at 20:32

2 votes

2 answers

388 views

Confusion about Liouville's theorem for Harmonic functions

asked May 27, 2019 at 15:35

2 votes

1 answer

73 views

Showing Homogeneity of norm $||(x,y)||=\sup_{0\leq\theta\leq 2\pi} || x \cos\theta + y\sin\theta ||$

asked Jan 22, 2020 at 14:06

1 vote

0 answers

175 views

Why is $b/\|w\|$ the offset of the hyperplane to the origin?

asked Apr 24, 2022 at 1:20

1 vote

1 answer

92 views

Can $X \setminus Y$ be first category? For $Y$ a proper linear subspace of a completely metrizable TVS $X$

asked Feb 25, 2020 at 14:22

1 vote

1 answer

42 views

Show the map $f(x)=\|Lx\|$ is a functional on the normed space $X$

asked Feb 28, 2020 at 16:19

1 vote

1 answer

1k views

Understanding the weak topology, and showing a function is weakly continuous

asked Feb 28, 2020 at 22:51

1 vote

3 answers

37 views

Are all elements $x$ in $c_0$ such that $\|x\|_\infty < \infty$

asked Mar 12, 2020 at 13:14

1 vote

0 answers

123 views

Showing that $\{ e^{int} \}$ form an orthonormal basis for $L_2 (S_1)$ [duplicate]

asked May 22, 2020 at 14:09

1 vote

1 answer

67 views

How to understand the $2 \times 2$ matrix representation of a linear operator

asked Jun 8, 2020 at 14:46

1 vote

2 answers

311 views

Meaning of $\setminus$ notation in Group Theory

asked Jul 15, 2019 at 13:15

1 vote

0 answers

35 views

Understanding Different definition of Balanced Set

asked Jan 9, 2020 at 19:41

1 vote

2 answers

92 views

Describe the region $\{|z^2 - 1|<1\}$ of the complex plane

asked May 7, 2019 at 14:10

1 vote

1 answer

207 views

Find a branch cut where $f(z)=\log_{\tau}(z^3 - 2)$ is holomorphic at $z=0$

asked May 10, 2019 at 20:06

1 vote

1 answer

351 views

Homeomorphism from punctured sphere to horn torus

asked Feb 5, 2019 at 13:07

1 vote

2 answers

3k views

Show $A$ is a Lebesgue Measurable set $\iff$ there exists $F_\sigma$ set such that $G_\delta$ set $m(G \setminus A) = m(A \setminus F) = 0$

asked Sep 5, 2018 at 15:20

0 votes

2 answers

52 views

Show there exists an $f $ s.t. $ \int_{B} f d\mathbb{P} = \int_{B} 1-f d\mathbb{Q} $

asked Nov 10, 2018 at 14:31

0 votes

1 answer

221 views

What is the basic idea of Topology

asked Nov 13, 2018 at 15:22

0 votes

1 answer

66 views

Show that there exists a measurable set $A\in\mathcal{A}$ such that $\chi_{A_n}\to\chi_{A}$ $\mu$-a.e.

asked Dec 11, 2018 at 18:23

0 votes

1 answer

56 views

Backing out the function knowing its Taylor Series

asked May 30, 2019 at 20:57

0 votes

3 answers

757 views

Classify the isolated singularities of $ \frac{z^5}{z^3 + z} $ and $ \frac{\cos z}{z^2 -1} $

asked Jun 19, 2019 at 12:00

0 votes

0 answers

74 views

What is a concise book for learning PDE at master's level?

asked Sep 3, 2020 at 12:34

0 votes

0 answers

32 views

Is every path connecting two distinct points in $\mathbb{R}^n$ homotopic to one another?

asked Oct 5 at 16:47

Stack Exchange Network

31 Questions

Proof that there exist only 17 Wallpaper Groups (Tilings of the plane)

When is the product of closed sets closed in the product topology?

Soft Question: Textbook for first graduate course in Functional Analysis

Combinatoric meaning to $1+2+\dots+n=\frac{n(n+1)}{2}= {n+1 \choose 2}$ [duplicate]

Integral of a function with respect to the measure $\nu(A)=\int_{A}fd\mu$

Prove that the measure of the image of G-delta set, $m(f(G))$, is the integral of the derivative, $\int_{G}f^{'} dm$

Find the complex roots of this quartic polynomial

Intuition behind definition of Connected Space in Topology

Confusion about Liouville's theorem for Harmonic functions

Showing Homogeneity of norm $||(x,y)||=\sup_{0\leq\theta\leq 2\pi} || x \cos\theta + y\sin\theta ||$

Why is $b/\|w\|$ the offset of the hyperplane to the origin?

Can $X \setminus Y$ be first category? For $Y$ a proper linear subspace of a completely metrizable TVS $X$

Show the map $f(x)=\|Lx\|$ is a functional on the normed space $X$

Understanding the weak topology, and showing a function is weakly continuous

Are all elements $x$ in $c_0$ such that $\|x\|_\infty < \infty$

Showing that $\{ e^{int} \}$ form an orthonormal basis for $L_2 (S_1)$ [duplicate]

How to understand the $2 \times 2$ matrix representation of a linear operator

Meaning of $\setminus$ notation in Group Theory

Understanding Different definition of Balanced Set

Describe the region $\{|z^2 - 1|<1\}$ of the complex plane

Find a branch cut where $f(z)=\log_{\tau}(z^3 - 2)$ is holomorphic at $z=0$

Homeomorphism from punctured sphere to horn torus

Show $A$ is a Lebesgue Measurable set $\iff$ there exists $F_\sigma$ set such that $G_\delta$ set $m(G \setminus A) = m(A \setminus F) = 0$

Show there exists an $f $ s.t. $ \int_{B} f d\mathbb{P} = \int_{B} 1-f d\mathbb{Q} $

What is the basic idea of Topology

Show that there exists a measurable set $A\in\mathcal{A}$ such that $\chi_{A_n}\to\chi_{A}$ $\mu$-a.e.

Backing out the function knowing its Taylor Series

Classify the isolated singularities of $ \frac{z^5}{z^3 + z} $ and $ \frac{\cos z}{z^2 -1} $

What is a concise book for learning PDE at master's level?

Is every path connecting two distinct points in $\mathbb{R}^n$ homotopic to one another?