Jonas Teuwen

6,871 reputation

11848

bio	website	fa.its.tudelft.nl/~teuwen
	location	Delft, Netherlands
	age	26
visits	member for	2 years, 9 months
	seen	8 hours ago
stats	profile views	3,416

About me

I'm a PhD candidate in analysis (harmonic analysis). I have a Master of Science degree in mathematics (analysis).

I am interested in many topics in analysis, but in particular: harmonic analysis, functional analysis, operator theory and special functions.

My email address is jonasteuwen@gmail.com.

I would appreciate it if you would correct my spelling and grammatical errors.

Me elsewhere

	6,871 reputation	bio	website	fa.its.tudelft.nl/~teuwen	visits	member for	2 years, 9 months
11848 badges		location	Delft, Netherlands		seen	8 hours ago

summary answers questions tags badges favorites bounties reputation activity

80 Favorites

added views newest activity votes

votes

answer

kviews

Does the open mapping theorem imply the Baire category theorem?

dec 10 at 23:50 Pedro Lauridsen Ribeiro 37

votes

answers

kviews

A Case Against the “Math Gene”

reference-request soft-question education

jun 7 '12 at 17:31 ex0du5 347

votes

answers

kviews

Induction on Real Numbers

induction

aug 12 at 23:55 Pete L. Clark 44.6k

votes

answers

638

views

Instructive proofs in functional analysis

analysis functional-analysis fourier-analysis big-list

oct 1 at 8:28 Norbert 20.4k

votes

answers

kviews

Is there an explicit isomorphism between $L^\infty[0,1]$ and $\ell^\infty$?

reference-request functional-analysis banach-spaces axiom-of-choice

feb 24 '12 at 15:25 t.b. 43.2k

votes

answers

kviews

Mathematical explanation behind a picture posted (lifted from facebook)

image-processing

aug 7 at 21:25 Community♦ 1

votes

answers

kviews

String Theory: What to do?

reference-request string-theory

nov 20 at 12:09 Javier Álvarez 4,794

votes

answers

542

views

Proving $\sum\limits_{l=1}^n \sum\limits _{k=1}^{n-1}\tan \frac {lk\pi }{2n+1}\tan \frac {l(k+1)\pi }{2n+1}=0$

sequences-and-series trigonometry

jul 22 at 12:42 robjohn♦ 59.9k

votes

answers

575

views

$f(x+1)=f(x)+1$ and $f(x^2)=f(x)^2$

functional-equations

aug 17 '11 at 13:49 Dijkschneier 80

votes

answers

kviews

Limits: How to evaluate $\lim\limits_{x\rightarrow \infty}\sqrt[n]{x^{n}+a_{n-1}x^{n-1}+\cdots+a_{0}}-x$

calculus limit faq

aug 29 '11 at 18:55 J. M. 38.9k

votes

answers

kviews

Norms on C[0, 1] inducing the same topology as the sup norm

homework real-analysis functional-analysis banach-spaces

jul 7 '11 at 5:34 t.b. 43.2k

votes

answers

723

views

What are all measurable maps $f:\mathbb C\to\mathbb C$ such that $f(ab)=f(a)f(b)$?

analysis

jul 19 '11 at 20:14 ccc 1,456

votes

answers

708

views

Is Banach-Alaoglu equivalent to AC?

functional-analysis set-theory axiom-of-choice

may 21 '12 at 14:50 t.b. 43.2k

votes

answer

769

views

Are these two Banach spaces isometrically isomorphic?

functional-analysis banach-spaces

nov 10 '11 at 15:55 Andrew 535

votes

answer

466

views

Accessible proof of Carleson's $L^2$ theorem

fourier-analysis fourier-series

nov 28 '10 at 0:52 Zarrax 19.7k

votes

answers

kviews

The union of a strictly increasing sequence of $\sigma$-algebras is not a $\sigma$-algebra

homework measure-theory

may 25 '12 at 15:14 Jonas Teuwen 6,871

votes

answers

769

views

Find a closed form for this sequence: $a_{n+1} = a_n + a_n^{-1}$

sequences-and-series recurrence-relations closed-form

sep 10 at 12:06 doraemonpaul 3,026

votes

answers

kviews

Exact values of $\cos(2\pi/7)$ and $\sin(2\pi/7)$

homework trigonometry

may 13 '12 at 21:43 Arturo Magidin 158k

votes

answers

278

views

non-trivial result about integrals due Gromov

calculus real-analysis

oct 18 '11 at 13:02 AD. 5,516

votes

answers

553

views

Clarifying the relationship between outer measures, measures and measurable spaces: the converse direction

measure-theory examples-counterexamples

dec 26 '11 at 21:01 Srivatsan 15.6k

votes

answers

351

views

Asymptotic behaviour of sums of consecutive powers

number-theory asymptotics

sep 13 '11 at 2:08 Srivatsan 15.6k

votes

answer

kviews

Cardinality of Borel sigma algebra

real-analysis measure-theory probability-theory set-theory descriptive-set-theory

oct 8 '11 at 23:22 ccc 1,456

votes

answers

kviews

The easy(?) part of IMO 2011 Problem 3

functional-equations contest-math

nov 3 '11 at 15:11 Hassan Muhammad 726

votes

answers

kviews

Intuition behind Conditional Expectation

probability-theory probability

feb 24 '11 at 23:08 Rasmus 9,458

votes

answers

kviews

The $\sigma$-algebra of subsets of $X$ generated by a set $\mathcal{A}$ is the smallest sigma algebra including $\mathcal{A}$

descriptive-set-theory measure-theory

apr 21 '12 at 21:32 Matt N. 15.3k

votes

answers

449

views

Is there a non-decreasing sequence $(a_n)$ such that $\sum 1/a_n=\infty$ and $\sum1/(n+a_n)<\infty$?

real-analysis sequences-and-series

nov 22 '11 at 9:28 David Mitra 41.1k

votes

answers

kviews

Stirling's formula: proof?

limit asymptotics gamma-function factorial

feb 29 '12 at 0:52 D. Thomine 1,532

votes

answers

779

views

Stuck trying to prove an inequality

inequality

oct 22 '11 at 23:02 robjohn♦ 59.9k

votes

answers

472

views

Euler's Constant: The asymptotic behavior of $\left(\sum\limits_{j=1}^{N} \frac{1}{j}\right) - \log(N)$

real-analysis limit asymptotics

dec 19 '11 at 22:38 N. S. 28k

votes

answers

309

views

What's the lower bound of the sum $S(n) = \sum_{k=1}^n \prod_{j=1}^k(1-\frac j n)$?

asymptotics

oct 10 '11 at 18:24 Eric 33.3k