sum of sequences converging to $0$
$begingroup$
Let $I$ a countable set of indices, and for any fixed $iin I$ let $(a^{(n)}_i)_{ninmathbb N}$ be a sequence with values in a non-archimedean local field (e.g. $mathbb Q_p$). Assume that the following hypotheses hold:
- For any $iin I$, $lim_{ntoinfty }a^{(n)}_i=0$.
- For any fixed $n$, all but finitely $a^{(n)}_i$ are equal to $0$. In other words the sum $sum_{iin I }a^{(n)}_i$ is finite.
Is it true that:
$$lim_{ntoinfty} sum_{iin I }a^{(n)}_i=sum_{iin I
}lim_{ntoinfty}a^{(n)}_i=0 ;;;;;text{?}$$
Remember that for non-archimedean fields: $sum_na_n$ converges if and only if $a_nto 0$
sequences-and-series analysis convergence local-field
$endgroup$
add a comment |
$begingroup$
Let $I$ a countable set of indices, and for any fixed $iin I$ let $(a^{(n)}_i)_{ninmathbb N}$ be a sequence with values in a non-archimedean local field (e.g. $mathbb Q_p$). Assume that the following hypotheses hold:
- For any $iin I$, $lim_{ntoinfty }a^{(n)}_i=0$.
- For any fixed $n$, all but finitely $a^{(n)}_i$ are equal to $0$. In other words the sum $sum_{iin I }a^{(n)}_i$ is finite.
Is it true that:
$$lim_{ntoinfty} sum_{iin I }a^{(n)}_i=sum_{iin I
}lim_{ntoinfty}a^{(n)}_i=0 ;;;;;text{?}$$
Remember that for non-archimedean fields: $sum_na_n$ converges if and only if $a_nto 0$
sequences-and-series analysis convergence local-field
$endgroup$
add a comment |
$begingroup$
Let $I$ a countable set of indices, and for any fixed $iin I$ let $(a^{(n)}_i)_{ninmathbb N}$ be a sequence with values in a non-archimedean local field (e.g. $mathbb Q_p$). Assume that the following hypotheses hold:
- For any $iin I$, $lim_{ntoinfty }a^{(n)}_i=0$.
- For any fixed $n$, all but finitely $a^{(n)}_i$ are equal to $0$. In other words the sum $sum_{iin I }a^{(n)}_i$ is finite.
Is it true that:
$$lim_{ntoinfty} sum_{iin I }a^{(n)}_i=sum_{iin I
}lim_{ntoinfty}a^{(n)}_i=0 ;;;;;text{?}$$
Remember that for non-archimedean fields: $sum_na_n$ converges if and only if $a_nto 0$
sequences-and-series analysis convergence local-field
$endgroup$
Let $I$ a countable set of indices, and for any fixed $iin I$ let $(a^{(n)}_i)_{ninmathbb N}$ be a sequence with values in a non-archimedean local field (e.g. $mathbb Q_p$). Assume that the following hypotheses hold:
- For any $iin I$, $lim_{ntoinfty }a^{(n)}_i=0$.
- For any fixed $n$, all but finitely $a^{(n)}_i$ are equal to $0$. In other words the sum $sum_{iin I }a^{(n)}_i$ is finite.
Is it true that:
$$lim_{ntoinfty} sum_{iin I }a^{(n)}_i=sum_{iin I
}lim_{ntoinfty}a^{(n)}_i=0 ;;;;;text{?}$$
Remember that for non-archimedean fields: $sum_na_n$ converges if and only if $a_nto 0$
sequences-and-series analysis convergence local-field
sequences-and-series analysis convergence local-field
edited Jan 23 at 19:24
manifold
asked Jan 23 at 19:17
manifoldmanifold
302213
302213
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Consider a list of sequences:
$$
a_1^{(n)}=1,0,0,0,0,dots
$$
$$
a_2^{(n)}=0,1,0,0,0,dots
$$
$$
a_3^{(n)}=0,0,1,0,0,dots
$$
$$
a_4^{(n)}=0,0,0,1,0,dots
$$
$$
vdots
$$
Then $sum_{iin I }a^{(n)}_i=1$ for any $n$.
$endgroup$
add a comment |
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%2f3084933%2fsum-of-sequences-converging-to-0%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Consider a list of sequences:
$$
a_1^{(n)}=1,0,0,0,0,dots
$$
$$
a_2^{(n)}=0,1,0,0,0,dots
$$
$$
a_3^{(n)}=0,0,1,0,0,dots
$$
$$
a_4^{(n)}=0,0,0,1,0,dots
$$
$$
vdots
$$
Then $sum_{iin I }a^{(n)}_i=1$ for any $n$.
$endgroup$
add a comment |
$begingroup$
Consider a list of sequences:
$$
a_1^{(n)}=1,0,0,0,0,dots
$$
$$
a_2^{(n)}=0,1,0,0,0,dots
$$
$$
a_3^{(n)}=0,0,1,0,0,dots
$$
$$
a_4^{(n)}=0,0,0,1,0,dots
$$
$$
vdots
$$
Then $sum_{iin I }a^{(n)}_i=1$ for any $n$.
$endgroup$
add a comment |
$begingroup$
Consider a list of sequences:
$$
a_1^{(n)}=1,0,0,0,0,dots
$$
$$
a_2^{(n)}=0,1,0,0,0,dots
$$
$$
a_3^{(n)}=0,0,1,0,0,dots
$$
$$
a_4^{(n)}=0,0,0,1,0,dots
$$
$$
vdots
$$
Then $sum_{iin I }a^{(n)}_i=1$ for any $n$.
$endgroup$
Consider a list of sequences:
$$
a_1^{(n)}=1,0,0,0,0,dots
$$
$$
a_2^{(n)}=0,1,0,0,0,dots
$$
$$
a_3^{(n)}=0,0,1,0,0,dots
$$
$$
a_4^{(n)}=0,0,0,1,0,dots
$$
$$
vdots
$$
Then $sum_{iin I }a^{(n)}_i=1$ for any $n$.
answered Jan 23 at 19:33
ZeeklessZeekless
577111
577111
add a comment |
add a comment |
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%2f3084933%2fsum-of-sequences-converging-to-0%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