What is the Fourier transform of the identity function? The 2019 Stack Overflow Developer Survey Results Are InWhat's the Fourier transform of these functions?Fourier transform of the identity function $f(x)=x$Fourier Transform Dirac DeltaDirac delta distribution and fourier transformFourier transform of distribution without physicist's $delta$-functionfourier transform normalization constantComputing Fourier TransformFormal derivation of the Fourier transform of Dirac delta using a distributionFourier transform using Dirac'sFourier Transform of Heaviside Step Function
Return to UK after being refused entry years previously
Multiply Two Integer Polynomials
Am I thawing this London Broil safely?
Can a flute soloist sit?
Does a dangling wire really electrocute me if I'm standing in water?
Button changing it's text & action. Good or terrible?
How to obtain Confidence Intervals for a LASSO regression?
What is the most effective way of iterating a std::vector and why?
Building a conditional check constraint
I see my dog run
Why can Shazam fly?
Does the shape of a die affect the probability of a number being rolled?
Should I use my personal e-mail address, or my workplace one, when registering to external websites for work purposes?
Where to refill my bottle in India?
Can someone be penalized for an "unlawful" act if no penalty is specified?
Falsification in Math vs Science
The difference between dialogue marks
Is there any way to tell whether the shot is going to hit you or not?
Are children permitted to help build the Beis Hamikdash?
What could be the right powersource for 15 seconds lifespan disposable giant chainsaw?
"as much details as you can remember"
Why isn't the circumferential light around the M87 black hole's event horizon symmetric?
Would the motor reverse if phases swapped for this case?
What does ひと匙 mean in this manga and has it been used colloquially?
What is the Fourier transform of the identity function?
The 2019 Stack Overflow Developer Survey Results Are InWhat's the Fourier transform of these functions?Fourier transform of the identity function $f(x)=x$Fourier Transform Dirac DeltaDirac delta distribution and fourier transformFourier transform of distribution without physicist's $delta$-functionfourier transform normalization constantComputing Fourier TransformFormal derivation of the Fourier transform of Dirac delta using a distributionFourier transform using Dirac'sFourier Transform of Heaviside Step Function
$begingroup$
How to find the Fourier transform of $x mapsto x$ using distribution $delta$?
Since $FT(1)=sqrt2pi delta(k)$ then $FT(x cdot 1)=sqrt2pi i delta'(k)$
But also since $1=d/dx (x)$ then $FT(x)=FT(1)/(ik)=delta(k)/(ik)$
Are both of these correct?
fourier-analysis fourier-transform distribution-theory dirac-delta
$endgroup$
add a comment |
$begingroup$
How to find the Fourier transform of $x mapsto x$ using distribution $delta$?
Since $FT(1)=sqrt2pi delta(k)$ then $FT(x cdot 1)=sqrt2pi i delta'(k)$
But also since $1=d/dx (x)$ then $FT(x)=FT(1)/(ik)=delta(k)/(ik)$
Are both of these correct?
fourier-analysis fourier-transform distribution-theory dirac-delta
$endgroup$
$begingroup$
You are not really allowed to write $delta(k)/k$ in distribution theory, but the best interpretation if this expressions is $-delta'(k)$.
$endgroup$
– md2perpe
Mar 30 at 16:22
$begingroup$
Your first derivation is correct.
$endgroup$
– md2perpe
Mar 30 at 16:26
$begingroup$
Your second derivation lacks a term $C , delta(k)$: $$sqrt2pi , delta(k) = FT(1) = FT(fracddxx) = ik , FT(x)$$ if and only if $$-sqrt2pi , delta'(k) + C , delta(k) = i , FT(x).$$
$endgroup$
– md2perpe
Mar 30 at 16:29
add a comment |
$begingroup$
How to find the Fourier transform of $x mapsto x$ using distribution $delta$?
Since $FT(1)=sqrt2pi delta(k)$ then $FT(x cdot 1)=sqrt2pi i delta'(k)$
But also since $1=d/dx (x)$ then $FT(x)=FT(1)/(ik)=delta(k)/(ik)$
Are both of these correct?
fourier-analysis fourier-transform distribution-theory dirac-delta
$endgroup$
How to find the Fourier transform of $x mapsto x$ using distribution $delta$?
Since $FT(1)=sqrt2pi delta(k)$ then $FT(x cdot 1)=sqrt2pi i delta'(k)$
But also since $1=d/dx (x)$ then $FT(x)=FT(1)/(ik)=delta(k)/(ik)$
Are both of these correct?
fourier-analysis fourier-transform distribution-theory dirac-delta
fourier-analysis fourier-transform distribution-theory dirac-delta
edited Mar 30 at 16:26
Rodrigo de Azevedo
13.2k41962
13.2k41962
asked Mar 30 at 16:15
SørënSørën
1009
1009
$begingroup$
You are not really allowed to write $delta(k)/k$ in distribution theory, but the best interpretation if this expressions is $-delta'(k)$.
$endgroup$
– md2perpe
Mar 30 at 16:22
$begingroup$
Your first derivation is correct.
$endgroup$
– md2perpe
Mar 30 at 16:26
$begingroup$
Your second derivation lacks a term $C , delta(k)$: $$sqrt2pi , delta(k) = FT(1) = FT(fracddxx) = ik , FT(x)$$ if and only if $$-sqrt2pi , delta'(k) + C , delta(k) = i , FT(x).$$
$endgroup$
– md2perpe
Mar 30 at 16:29
add a comment |
$begingroup$
You are not really allowed to write $delta(k)/k$ in distribution theory, but the best interpretation if this expressions is $-delta'(k)$.
$endgroup$
– md2perpe
Mar 30 at 16:22
$begingroup$
Your first derivation is correct.
$endgroup$
– md2perpe
Mar 30 at 16:26
$begingroup$
Your second derivation lacks a term $C , delta(k)$: $$sqrt2pi , delta(k) = FT(1) = FT(fracddxx) = ik , FT(x)$$ if and only if $$-sqrt2pi , delta'(k) + C , delta(k) = i , FT(x).$$
$endgroup$
– md2perpe
Mar 30 at 16:29
$begingroup$
You are not really allowed to write $delta(k)/k$ in distribution theory, but the best interpretation if this expressions is $-delta'(k)$.
$endgroup$
– md2perpe
Mar 30 at 16:22
$begingroup$
You are not really allowed to write $delta(k)/k$ in distribution theory, but the best interpretation if this expressions is $-delta'(k)$.
$endgroup$
– md2perpe
Mar 30 at 16:22
$begingroup$
Your first derivation is correct.
$endgroup$
– md2perpe
Mar 30 at 16:26
$begingroup$
Your first derivation is correct.
$endgroup$
– md2perpe
Mar 30 at 16:26
$begingroup$
Your second derivation lacks a term $C , delta(k)$: $$sqrt2pi , delta(k) = FT(1) = FT(fracddxx) = ik , FT(x)$$ if and only if $$-sqrt2pi , delta'(k) + C , delta(k) = i , FT(x).$$
$endgroup$
– md2perpe
Mar 30 at 16:29
$begingroup$
Your second derivation lacks a term $C , delta(k)$: $$sqrt2pi , delta(k) = FT(1) = FT(fracddxx) = ik , FT(x)$$ if and only if $$-sqrt2pi , delta'(k) + C , delta(k) = i , FT(x).$$
$endgroup$
– md2perpe
Mar 30 at 16:29
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "69"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3168461%2fwhat-is-the-fourier-transform-of-the-identity-function%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3168461%2fwhat-is-the-fourier-transform-of-the-identity-function%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
You are not really allowed to write $delta(k)/k$ in distribution theory, but the best interpretation if this expressions is $-delta'(k)$.
$endgroup$
– md2perpe
Mar 30 at 16:22
$begingroup$
Your first derivation is correct.
$endgroup$
– md2perpe
Mar 30 at 16:26
$begingroup$
Your second derivation lacks a term $C , delta(k)$: $$sqrt2pi , delta(k) = FT(1) = FT(fracddxx) = ik , FT(x)$$ if and only if $$-sqrt2pi , delta'(k) + C , delta(k) = i , FT(x).$$
$endgroup$
– md2perpe
Mar 30 at 16:29