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Questions tagged [gauge-integral]

For questions about Henstock-Kurzweil integral or gauge integral.

4 votes
1 answer
117 views

Call $f:I\to F$ gauge integrable where $I = [a, b]$ is a compact interval and $F$ is a Banach space, if the usual definition holds like if $F = \mathbb{R}$, just replace absolute value by norm. How ...
Jakobian's user avatar
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4 votes
0 answers
55 views

Let $\mathcal{HK}(I)$ denote the Henstock-Kurzweil integrable functions on $I$. By mimicking the case for Lebesgue integral I've proven the following: Theorem $1$. Let $F$ be an indefinite integral of ...
Jakobian's user avatar
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2 votes
1 answer
70 views

Let $\mathcal{R}^*(I)$ be the set of gauge integrable (generalized Riemann integrable) functions $f:I\to \mathbb{R}$ where $I = [a, b]$. Say that a point $c\in [a, b]$ is a singular for $f\in \mathcal{...
Jakobian's user avatar
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1 vote
1 answer
137 views

Bartle's book, Modern theory of integration, focuses on Henstock-Kurzweil integrals, where $\mathcal{R}^*(I)$ denotes the set of Henstock-Kurzweil integrable functions on $I = [a, b]$. Also, $\mathcal{...
Jakobian's user avatar
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5 votes
1 answer
260 views

This question is based on this post, where in the comments, Toby Bartels conjectures that every Henstock-Kurzweil (gauge) integrable function $f\in\mathcal{HK}$ can be expressed as $f= g + h$ for a ...
user avatar
2 votes
0 answers
68 views

One example of a function that is Henstock-Kurzweil integrable but not Lebesgue integrable is $f(x) = \frac{1}{x} \cos\left(\frac{1}{x^2}\right)$ on $[0, 1]$. However, $f$ only fails to be locally-...
perplexed's user avatar
  • 336
8 votes
1 answer
531 views

I've stumbled upon a mention of Cousin's theorem in the context of Henstock–Kurzweil integral and got confused. I do not understand why this fact is called a theorem and what makes it any remarkable, ...
Alexey's user avatar
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1 vote
0 answers
83 views

I am comparing two ways of defining the integral along a path of a function of complex domain and value. One is the one given in Conway's Functions of one Complex Variable and the other is given in ...
Juan's user avatar
  • 637
5 votes
1 answer
252 views

I was wondering about how Fourier series behaves in the setting of Henstock-Kurzweil integration. For example, the non-Lebesgue-integrable function $f(x) = \dfrac{1}{x}\mathrm{e}^{\mathrm{i}/x}$ can ...
Jianing Song's user avatar
  • 2,783
3 votes
1 answer
346 views

Treating the Riemann integral in a constructive setting is easy and straightforward. Treating the closely related but much more powerful Henstock-Kurzweil integral constructively is almost easy, ...
saolof's user avatar
  • 695
6 votes
0 answers
70 views

The set of Lebesgue integrable functions form a lattice under pointwise min and max (also more generally for R, Henstock-Kurzweil integrable functions with an upper or lower bound form a lattice as ...
saolof's user avatar
  • 695
11 votes
3 answers
720 views

It is well known that the Henstock–Kurzweil integral fixes a lot of issues with trying to integrate derivatives. The second fundamental theorem of calculus for this integral states: Given that $f : [...
Sam Forster's user avatar
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1 vote
0 answers
95 views

If I am understanding, the law of large numbers correctly, one implication is this: Let $\lambda$ be the Lebesgue measure on $[0,1]$. Let $f_1,f_2,\dots,$ be functions, $[0,1] \rightarrow \mathbb{R}$, ...
user253846's user avatar
1 vote
1 answer
77 views

I have tried to prove this using the Cauchy criterion for HK-integration but I have been unsuccessful thus far. I have various fancy theorems at my disposal such the MCT and the DCT but I can not ...
David's user avatar
  • 882
2 votes
0 answers
45 views

I doubt if this interval is true and satisfy this $$ x_{i-1}^{2} < \xi_{i}^{2} - \dfrac{1}{3}(x_{i}^{2} + x_{i}x_{i-1} + x_{i-1}^{2}) < x_{i}^{2} < 2\delta^{2}.$$ here is example $$\int_{a}...
notorious's user avatar

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