What is the complete definition of inner product space












0












$begingroup$


There are some contradicting and confusing definitions online and I am trying to figure out the general case definition.



For example it is seems that order between elements in the range of the inner product should be defined, but I never saw it being mentioned explicitly.



Must the range of the inner product be part of the field that is used to construct the vector space itself? For example it could be the vectors from the vector space, and since scalar vector multiplication is defined, there is no contradiction in the definition.



Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?










share|cite|improve this question









$endgroup$












  • $begingroup$
    Typically, if not always, an inner product space is either a real or complex vector space (and the inner product always takes values in the scalar field).
    $endgroup$
    – David C. Ullrich
    Jan 15 at 14:18










  • $begingroup$
    "Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?" I think you mean the requirement is changed from bilinearity to sesquilinearity. The latter is general, because complex conjugation reduces on $Bbb R$ to the identity operation.
    $endgroup$
    – J.G.
    Jan 15 at 15:19
















0












$begingroup$


There are some contradicting and confusing definitions online and I am trying to figure out the general case definition.



For example it is seems that order between elements in the range of the inner product should be defined, but I never saw it being mentioned explicitly.



Must the range of the inner product be part of the field that is used to construct the vector space itself? For example it could be the vectors from the vector space, and since scalar vector multiplication is defined, there is no contradiction in the definition.



Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?










share|cite|improve this question









$endgroup$












  • $begingroup$
    Typically, if not always, an inner product space is either a real or complex vector space (and the inner product always takes values in the scalar field).
    $endgroup$
    – David C. Ullrich
    Jan 15 at 14:18










  • $begingroup$
    "Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?" I think you mean the requirement is changed from bilinearity to sesquilinearity. The latter is general, because complex conjugation reduces on $Bbb R$ to the identity operation.
    $endgroup$
    – J.G.
    Jan 15 at 15:19














0












0








0





$begingroup$


There are some contradicting and confusing definitions online and I am trying to figure out the general case definition.



For example it is seems that order between elements in the range of the inner product should be defined, but I never saw it being mentioned explicitly.



Must the range of the inner product be part of the field that is used to construct the vector space itself? For example it could be the vectors from the vector space, and since scalar vector multiplication is defined, there is no contradiction in the definition.



Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?










share|cite|improve this question









$endgroup$




There are some contradicting and confusing definitions online and I am trying to figure out the general case definition.



For example it is seems that order between elements in the range of the inner product should be defined, but I never saw it being mentioned explicitly.



Must the range of the inner product be part of the field that is used to construct the vector space itself? For example it could be the vectors from the vector space, and since scalar vector multiplication is defined, there is no contradiction in the definition.



Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?







linear-algebra






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 15 at 13:22









ArtiumArtium

4881618




4881618












  • $begingroup$
    Typically, if not always, an inner product space is either a real or complex vector space (and the inner product always takes values in the scalar field).
    $endgroup$
    – David C. Ullrich
    Jan 15 at 14:18










  • $begingroup$
    "Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?" I think you mean the requirement is changed from bilinearity to sesquilinearity. The latter is general, because complex conjugation reduces on $Bbb R$ to the identity operation.
    $endgroup$
    – J.G.
    Jan 15 at 15:19


















  • $begingroup$
    Typically, if not always, an inner product space is either a real or complex vector space (and the inner product always takes values in the scalar field).
    $endgroup$
    – David C. Ullrich
    Jan 15 at 14:18










  • $begingroup$
    "Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?" I think you mean the requirement is changed from bilinearity to sesquilinearity. The latter is general, because complex conjugation reduces on $Bbb R$ to the identity operation.
    $endgroup$
    – J.G.
    Jan 15 at 15:19
















$begingroup$
Typically, if not always, an inner product space is either a real or complex vector space (and the inner product always takes values in the scalar field).
$endgroup$
– David C. Ullrich
Jan 15 at 14:18




$begingroup$
Typically, if not always, an inner product space is either a real or complex vector space (and the inner product always takes values in the scalar field).
$endgroup$
– David C. Ullrich
Jan 15 at 14:18












$begingroup$
"Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?" I think you mean the requirement is changed from bilinearity to sesquilinearity. The latter is general, because complex conjugation reduces on $Bbb R$ to the identity operation.
$endgroup$
– J.G.
Jan 15 at 15:19




$begingroup$
"Is linearity part of the definition? When the field is complex numbers, it seems that the definition is altered a little bit. So what is the definition for the general case?" I think you mean the requirement is changed from bilinearity to sesquilinearity. The latter is general, because complex conjugation reduces on $Bbb R$ to the identity operation.
$endgroup$
– J.G.
Jan 15 at 15:19










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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3074421%2fwhat-is-the-complete-definition-of-inner-product-space%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
















draft saved

draft discarded




















































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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3074421%2fwhat-is-the-complete-definition-of-inner-product-space%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

The term 'EXEC' is not recognized as the name of a cmdlet Powershell

NPM command prompt closes immediately [closed]

Error binding properties and functions in emscripten