Understanding homomorphism from coalgebra to algebra
$begingroup$
Could someone please explain what exactly a homomorphism from coalgebra to algebra (from this paper: 1, page 10, definition 5.1). I understand a homomorphism as a map between two structures which preserves operations and their neutral elements, but which operations would it preserve between coalgebra and algebra? Thank you.
hopf-algebras
$endgroup$
add a comment |
$begingroup$
Could someone please explain what exactly a homomorphism from coalgebra to algebra (from this paper: 1, page 10, definition 5.1). I understand a homomorphism as a map between two structures which preserves operations and their neutral elements, but which operations would it preserve between coalgebra and algebra? Thank you.
hopf-algebras
$endgroup$
$begingroup$
Usually this is done if the domain and range are bialgebras, so they have both a product and a coproduct.
$endgroup$
– Matt Samuel
Jan 6 at 15:46
$begingroup$
Maybe linear map from coalgebra to algebra makes more sense, but I still don't understand how it can be defined. Found it there: maths.qmul.ac.uk/~whitty/LSBU/MathsStudyGroup/SeligHopf.pdf , on page 5, section 4 (in the beginning).
$endgroup$
– Ordev Agens
Jan 7 at 18:31
1
$begingroup$
Well it defines it explicitly with a formula. And it's exactly as I said: it's a map between bialgebras (specifically here a bialgebra with itself). In terms of linear maps, you can define a nontrivial linear map between any two nontrivial vector spaces over the same field. It's not a homomorphism, it's just a composition of particular important functions here, including the product and the coproduct.
$endgroup$
– Matt Samuel
Jan 7 at 19:22
$begingroup$
Thank you for explaining. So a linear map from coalgebra ($A$, $mu$, $nu$) to algebra ($A$, $Delta$, $epsilon$) is just a linear map $Ato A$?
$endgroup$
– Ordev Agens
Jan 7 at 19:47
1
$begingroup$
Yes it is. Comment too short.
$endgroup$
– Matt Samuel
Jan 7 at 20:36
add a comment |
$begingroup$
Could someone please explain what exactly a homomorphism from coalgebra to algebra (from this paper: 1, page 10, definition 5.1). I understand a homomorphism as a map between two structures which preserves operations and their neutral elements, but which operations would it preserve between coalgebra and algebra? Thank you.
hopf-algebras
$endgroup$
Could someone please explain what exactly a homomorphism from coalgebra to algebra (from this paper: 1, page 10, definition 5.1). I understand a homomorphism as a map between two structures which preserves operations and their neutral elements, but which operations would it preserve between coalgebra and algebra? Thank you.
hopf-algebras
hopf-algebras
asked Jan 6 at 13:02
Ordev AgensOrdev Agens
205
205
$begingroup$
Usually this is done if the domain and range are bialgebras, so they have both a product and a coproduct.
$endgroup$
– Matt Samuel
Jan 6 at 15:46
$begingroup$
Maybe linear map from coalgebra to algebra makes more sense, but I still don't understand how it can be defined. Found it there: maths.qmul.ac.uk/~whitty/LSBU/MathsStudyGroup/SeligHopf.pdf , on page 5, section 4 (in the beginning).
$endgroup$
– Ordev Agens
Jan 7 at 18:31
1
$begingroup$
Well it defines it explicitly with a formula. And it's exactly as I said: it's a map between bialgebras (specifically here a bialgebra with itself). In terms of linear maps, you can define a nontrivial linear map between any two nontrivial vector spaces over the same field. It's not a homomorphism, it's just a composition of particular important functions here, including the product and the coproduct.
$endgroup$
– Matt Samuel
Jan 7 at 19:22
$begingroup$
Thank you for explaining. So a linear map from coalgebra ($A$, $mu$, $nu$) to algebra ($A$, $Delta$, $epsilon$) is just a linear map $Ato A$?
$endgroup$
– Ordev Agens
Jan 7 at 19:47
1
$begingroup$
Yes it is. Comment too short.
$endgroup$
– Matt Samuel
Jan 7 at 20:36
add a comment |
$begingroup$
Usually this is done if the domain and range are bialgebras, so they have both a product and a coproduct.
$endgroup$
– Matt Samuel
Jan 6 at 15:46
$begingroup$
Maybe linear map from coalgebra to algebra makes more sense, but I still don't understand how it can be defined. Found it there: maths.qmul.ac.uk/~whitty/LSBU/MathsStudyGroup/SeligHopf.pdf , on page 5, section 4 (in the beginning).
$endgroup$
– Ordev Agens
Jan 7 at 18:31
1
$begingroup$
Well it defines it explicitly with a formula. And it's exactly as I said: it's a map between bialgebras (specifically here a bialgebra with itself). In terms of linear maps, you can define a nontrivial linear map between any two nontrivial vector spaces over the same field. It's not a homomorphism, it's just a composition of particular important functions here, including the product and the coproduct.
$endgroup$
– Matt Samuel
Jan 7 at 19:22
$begingroup$
Thank you for explaining. So a linear map from coalgebra ($A$, $mu$, $nu$) to algebra ($A$, $Delta$, $epsilon$) is just a linear map $Ato A$?
$endgroup$
– Ordev Agens
Jan 7 at 19:47
1
$begingroup$
Yes it is. Comment too short.
$endgroup$
– Matt Samuel
Jan 7 at 20:36
$begingroup$
Usually this is done if the domain and range are bialgebras, so they have both a product and a coproduct.
$endgroup$
– Matt Samuel
Jan 6 at 15:46
$begingroup$
Usually this is done if the domain and range are bialgebras, so they have both a product and a coproduct.
$endgroup$
– Matt Samuel
Jan 6 at 15:46
$begingroup$
Maybe linear map from coalgebra to algebra makes more sense, but I still don't understand how it can be defined. Found it there: maths.qmul.ac.uk/~whitty/LSBU/MathsStudyGroup/SeligHopf.pdf , on page 5, section 4 (in the beginning).
$endgroup$
– Ordev Agens
Jan 7 at 18:31
$begingroup$
Maybe linear map from coalgebra to algebra makes more sense, but I still don't understand how it can be defined. Found it there: maths.qmul.ac.uk/~whitty/LSBU/MathsStudyGroup/SeligHopf.pdf , on page 5, section 4 (in the beginning).
$endgroup$
– Ordev Agens
Jan 7 at 18:31
1
1
$begingroup$
Well it defines it explicitly with a formula. And it's exactly as I said: it's a map between bialgebras (specifically here a bialgebra with itself). In terms of linear maps, you can define a nontrivial linear map between any two nontrivial vector spaces over the same field. It's not a homomorphism, it's just a composition of particular important functions here, including the product and the coproduct.
$endgroup$
– Matt Samuel
Jan 7 at 19:22
$begingroup$
Well it defines it explicitly with a formula. And it's exactly as I said: it's a map between bialgebras (specifically here a bialgebra with itself). In terms of linear maps, you can define a nontrivial linear map between any two nontrivial vector spaces over the same field. It's not a homomorphism, it's just a composition of particular important functions here, including the product and the coproduct.
$endgroup$
– Matt Samuel
Jan 7 at 19:22
$begingroup$
Thank you for explaining. So a linear map from coalgebra ($A$, $mu$, $nu$) to algebra ($A$, $Delta$, $epsilon$) is just a linear map $Ato A$?
$endgroup$
– Ordev Agens
Jan 7 at 19:47
$begingroup$
Thank you for explaining. So a linear map from coalgebra ($A$, $mu$, $nu$) to algebra ($A$, $Delta$, $epsilon$) is just a linear map $Ato A$?
$endgroup$
– Ordev Agens
Jan 7 at 19:47
1
1
$begingroup$
Yes it is. Comment too short.
$endgroup$
– Matt Samuel
Jan 7 at 20:36
$begingroup$
Yes it is. Comment too short.
$endgroup$
– Matt Samuel
Jan 7 at 20:36
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%2f3063833%2funderstanding-homomorphism-from-coalgebra-to-algebra%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%2f3063833%2funderstanding-homomorphism-from-coalgebra-to-algebra%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
$begingroup$
Usually this is done if the domain and range are bialgebras, so they have both a product and a coproduct.
$endgroup$
– Matt Samuel
Jan 6 at 15:46
$begingroup$
Maybe linear map from coalgebra to algebra makes more sense, but I still don't understand how it can be defined. Found it there: maths.qmul.ac.uk/~whitty/LSBU/MathsStudyGroup/SeligHopf.pdf , on page 5, section 4 (in the beginning).
$endgroup$
– Ordev Agens
Jan 7 at 18:31
1
$begingroup$
Well it defines it explicitly with a formula. And it's exactly as I said: it's a map between bialgebras (specifically here a bialgebra with itself). In terms of linear maps, you can define a nontrivial linear map between any two nontrivial vector spaces over the same field. It's not a homomorphism, it's just a composition of particular important functions here, including the product and the coproduct.
$endgroup$
– Matt Samuel
Jan 7 at 19:22
$begingroup$
Thank you for explaining. So a linear map from coalgebra ($A$, $mu$, $nu$) to algebra ($A$, $Delta$, $epsilon$) is just a linear map $Ato A$?
$endgroup$
– Ordev Agens
Jan 7 at 19:47
1
$begingroup$
Yes it is. Comment too short.
$endgroup$
– Matt Samuel
Jan 7 at 20:36