Invariants between two isomorphic vector spacesComplex vector spacesSimple questions about isomorphisms between vector spacesWhat is needed to make Euclidean spaces isomorphic as groups?Vector Spaces and GroupsWhat do mathematicians mean by if two vector spaces are isomorphic, then “they are the same”What are the implications of the fact that vector spaces are isomorphic?Assume that $V$ and $W$ are isomorphic vector spaces. What does it imply if $V$ and $W$ are not finite dimensional.If there is a bijective linear transformation between two vector spaces, do they bear same properties?Are $C[0,1]$ and $C[0,1)$ isomorphic?Subspaces and elements of isomorphic vector spaces

Tiptoe or tiphoof? Adjusting words to better fit fantasy races

how to analyze "是其于主也至忠矣"

Do I need a multiple entry visa for a trip UK -> Sweden -> UK?

Will it be accepted, if there is no ''Main Character" stereotype?

Select empty space and change color in vector

Was the picture area of a CRT a parallelogram (instead of a true rectangle)?

Revision Lecture, what are the aims?

How can I use the arrow sign in my bash prompt?

The plural of 'stomach"

Why is delta-v is the most useful quantity for planning space travel?

How does residential electricity work?

Why Were Madagascar and New Zealand Discovered So Late?

Why did Kant, Hegel, and Adorno leave some words and phrases in the Greek alphabet?

General airship questions: largest possible size?

How do I rename a LINUX host without needing to reboot for the rename to take effect?

Finding all intervals that match predicate in vector

Is there a good way to store credentials outside of a password manager?

What is the oldest known work of fiction?

Best way to store options for panels

Modify casing of marked letters

Using parameter substitution on a Bash array

What's a natural way to say that someone works somewhere (for a job)?

What would be the benefits of having both a state and local currencies?

apt-get update is failing in debian



Invariants between two isomorphic vector spaces


Complex vector spacesSimple questions about isomorphisms between vector spacesWhat is needed to make Euclidean spaces isomorphic as groups?Vector Spaces and GroupsWhat do mathematicians mean by if two vector spaces are isomorphic, then “they are the same”What are the implications of the fact that vector spaces are isomorphic?Assume that $V$ and $W$ are isomorphic vector spaces. What does it imply if $V$ and $W$ are not finite dimensional.If there is a bijective linear transformation between two vector spaces, do they bear same properties?Are $C[0,1]$ and $C[0,1)$ isomorphic?Subspaces and elements of isomorphic vector spaces













2












$begingroup$


I have a general question about isomorphisms between vector spaces.



From a general point of view, there are common properties (invariants) between two isomorphic structures (e.g., properties about compactness or connectedness between two isomorphic topological spaces, commutativity between two isomorphic groups). Can you give me some examples of invariants between two isomorphic vector spaces ?



Thank you for your help !










share|cite|improve this question











$endgroup$







  • 1




    $begingroup$
    Dimension certainly.
    $endgroup$
    – Wuestenfux
    4 hours ago















2












$begingroup$


I have a general question about isomorphisms between vector spaces.



From a general point of view, there are common properties (invariants) between two isomorphic structures (e.g., properties about compactness or connectedness between two isomorphic topological spaces, commutativity between two isomorphic groups). Can you give me some examples of invariants between two isomorphic vector spaces ?



Thank you for your help !










share|cite|improve this question











$endgroup$







  • 1




    $begingroup$
    Dimension certainly.
    $endgroup$
    – Wuestenfux
    4 hours ago













2












2








2





$begingroup$


I have a general question about isomorphisms between vector spaces.



From a general point of view, there are common properties (invariants) between two isomorphic structures (e.g., properties about compactness or connectedness between two isomorphic topological spaces, commutativity between two isomorphic groups). Can you give me some examples of invariants between two isomorphic vector spaces ?



Thank you for your help !










share|cite|improve this question











$endgroup$




I have a general question about isomorphisms between vector spaces.



From a general point of view, there are common properties (invariants) between two isomorphic structures (e.g., properties about compactness or connectedness between two isomorphic topological spaces, commutativity between two isomorphic groups). Can you give me some examples of invariants between two isomorphic vector spaces ?



Thank you for your help !







vector-spaces vector-space-isomorphism invariance






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited 4 hours ago









José Carlos Santos

170k23132238




170k23132238










asked 5 hours ago









deeppinkwaterdeeppinkwater

858




858







  • 1




    $begingroup$
    Dimension certainly.
    $endgroup$
    – Wuestenfux
    4 hours ago












  • 1




    $begingroup$
    Dimension certainly.
    $endgroup$
    – Wuestenfux
    4 hours ago







1




1




$begingroup$
Dimension certainly.
$endgroup$
– Wuestenfux
4 hours ago




$begingroup$
Dimension certainly.
$endgroup$
– Wuestenfux
4 hours ago










2 Answers
2






active

oldest

votes


















3












$begingroup$

One of the fundamental theorems of linear algebra is that there is only one invariant you really need to care about: the dimension. Two vector spaces are isomorphic if and only if they have the same dimension. The reason is that any map that bijectively takes a basis of one vector space to a basis of another vector space must extend linearly (in a unique way) to a vector space isomorphism.



Another example is the cardinality of the underlying set (of course, the isomorphism is a bijection).



This observation is actually useful in field theory. Suppose you have a field $K$ which you know is finite. Then the prime subfield of $K$ is $mathbbF_p$ for some prime $p.$ Now $K$ must have finite dimension (since $K$ is finite), so $K=(mathbbF_p)^r$ for some $r.$ It follows immediately that $lvertKrvert=p^r$ for some $r.$ Moreover, if two finite fields are of the same cardinality, then that cardinality must be $p^r$ for some prime $p$ and some integer $r,$ and it follows that those two fields are isomorphic as vector spaces over the prime subfield $mathbbF_p.$ (With a bit more work, one can show that any two finite fields of the same cardinality are isomorphic as fields, and that a finite field of cardinality $p^r$ does exist for every prime $p$ and every integer $r>0.$)






share|cite|improve this answer











$endgroup$












  • $begingroup$
    Thank you for this answer.
    $endgroup$
    – deeppinkwater
    4 hours ago










  • $begingroup$
    @deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
    $endgroup$
    – Will R
    2 hours ago



















2












$begingroup$

The number one is the dimension, of course, since two vector spaces over the same field are isomorphic if and only if they have the same dimension.






share|cite|improve this answer









$endgroup$












  • $begingroup$
    Thank you, that's the only one that came to my mind actually !
    $endgroup$
    – deeppinkwater
    4 hours ago










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%2f3163230%2finvariants-between-two-isomorphic-vector-spaces%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown

























2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









3












$begingroup$

One of the fundamental theorems of linear algebra is that there is only one invariant you really need to care about: the dimension. Two vector spaces are isomorphic if and only if they have the same dimension. The reason is that any map that bijectively takes a basis of one vector space to a basis of another vector space must extend linearly (in a unique way) to a vector space isomorphism.



Another example is the cardinality of the underlying set (of course, the isomorphism is a bijection).



This observation is actually useful in field theory. Suppose you have a field $K$ which you know is finite. Then the prime subfield of $K$ is $mathbbF_p$ for some prime $p.$ Now $K$ must have finite dimension (since $K$ is finite), so $K=(mathbbF_p)^r$ for some $r.$ It follows immediately that $lvertKrvert=p^r$ for some $r.$ Moreover, if two finite fields are of the same cardinality, then that cardinality must be $p^r$ for some prime $p$ and some integer $r,$ and it follows that those two fields are isomorphic as vector spaces over the prime subfield $mathbbF_p.$ (With a bit more work, one can show that any two finite fields of the same cardinality are isomorphic as fields, and that a finite field of cardinality $p^r$ does exist for every prime $p$ and every integer $r>0.$)






share|cite|improve this answer











$endgroup$












  • $begingroup$
    Thank you for this answer.
    $endgroup$
    – deeppinkwater
    4 hours ago










  • $begingroup$
    @deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
    $endgroup$
    – Will R
    2 hours ago
















3












$begingroup$

One of the fundamental theorems of linear algebra is that there is only one invariant you really need to care about: the dimension. Two vector spaces are isomorphic if and only if they have the same dimension. The reason is that any map that bijectively takes a basis of one vector space to a basis of another vector space must extend linearly (in a unique way) to a vector space isomorphism.



Another example is the cardinality of the underlying set (of course, the isomorphism is a bijection).



This observation is actually useful in field theory. Suppose you have a field $K$ which you know is finite. Then the prime subfield of $K$ is $mathbbF_p$ for some prime $p.$ Now $K$ must have finite dimension (since $K$ is finite), so $K=(mathbbF_p)^r$ for some $r.$ It follows immediately that $lvertKrvert=p^r$ for some $r.$ Moreover, if two finite fields are of the same cardinality, then that cardinality must be $p^r$ for some prime $p$ and some integer $r,$ and it follows that those two fields are isomorphic as vector spaces over the prime subfield $mathbbF_p.$ (With a bit more work, one can show that any two finite fields of the same cardinality are isomorphic as fields, and that a finite field of cardinality $p^r$ does exist for every prime $p$ and every integer $r>0.$)






share|cite|improve this answer











$endgroup$












  • $begingroup$
    Thank you for this answer.
    $endgroup$
    – deeppinkwater
    4 hours ago










  • $begingroup$
    @deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
    $endgroup$
    – Will R
    2 hours ago














3












3








3





$begingroup$

One of the fundamental theorems of linear algebra is that there is only one invariant you really need to care about: the dimension. Two vector spaces are isomorphic if and only if they have the same dimension. The reason is that any map that bijectively takes a basis of one vector space to a basis of another vector space must extend linearly (in a unique way) to a vector space isomorphism.



Another example is the cardinality of the underlying set (of course, the isomorphism is a bijection).



This observation is actually useful in field theory. Suppose you have a field $K$ which you know is finite. Then the prime subfield of $K$ is $mathbbF_p$ for some prime $p.$ Now $K$ must have finite dimension (since $K$ is finite), so $K=(mathbbF_p)^r$ for some $r.$ It follows immediately that $lvertKrvert=p^r$ for some $r.$ Moreover, if two finite fields are of the same cardinality, then that cardinality must be $p^r$ for some prime $p$ and some integer $r,$ and it follows that those two fields are isomorphic as vector spaces over the prime subfield $mathbbF_p.$ (With a bit more work, one can show that any two finite fields of the same cardinality are isomorphic as fields, and that a finite field of cardinality $p^r$ does exist for every prime $p$ and every integer $r>0.$)






share|cite|improve this answer











$endgroup$



One of the fundamental theorems of linear algebra is that there is only one invariant you really need to care about: the dimension. Two vector spaces are isomorphic if and only if they have the same dimension. The reason is that any map that bijectively takes a basis of one vector space to a basis of another vector space must extend linearly (in a unique way) to a vector space isomorphism.



Another example is the cardinality of the underlying set (of course, the isomorphism is a bijection).



This observation is actually useful in field theory. Suppose you have a field $K$ which you know is finite. Then the prime subfield of $K$ is $mathbbF_p$ for some prime $p.$ Now $K$ must have finite dimension (since $K$ is finite), so $K=(mathbbF_p)^r$ for some $r.$ It follows immediately that $lvertKrvert=p^r$ for some $r.$ Moreover, if two finite fields are of the same cardinality, then that cardinality must be $p^r$ for some prime $p$ and some integer $r,$ and it follows that those two fields are isomorphic as vector spaces over the prime subfield $mathbbF_p.$ (With a bit more work, one can show that any two finite fields of the same cardinality are isomorphic as fields, and that a finite field of cardinality $p^r$ does exist for every prime $p$ and every integer $r>0.$)







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited 4 hours ago

























answered 4 hours ago









Will RWill R

6,75231429




6,75231429











  • $begingroup$
    Thank you for this answer.
    $endgroup$
    – deeppinkwater
    4 hours ago










  • $begingroup$
    @deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
    $endgroup$
    – Will R
    2 hours ago

















  • $begingroup$
    Thank you for this answer.
    $endgroup$
    – deeppinkwater
    4 hours ago










  • $begingroup$
    @deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
    $endgroup$
    – Will R
    2 hours ago
















$begingroup$
Thank you for this answer.
$endgroup$
– deeppinkwater
4 hours ago




$begingroup$
Thank you for this answer.
$endgroup$
– deeppinkwater
4 hours ago












$begingroup$
@deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
$endgroup$
– Will R
2 hours ago





$begingroup$
@deeppinkwater: It is perhaps also worth noting that although (or rather, because!) the dimension is the only thing that determines the isomorphism class of a vector space, most linear algebra courses actually spend more time focusing on the linear maps between vector spaces. Then there are lots of "invariants", depending upon your notion of isomorphism, the primary examples being eigenvalues (with their respective multiplicities), and therefore also the determinant and the trace, and the singular values.
$endgroup$
– Will R
2 hours ago












2












$begingroup$

The number one is the dimension, of course, since two vector spaces over the same field are isomorphic if and only if they have the same dimension.






share|cite|improve this answer









$endgroup$












  • $begingroup$
    Thank you, that's the only one that came to my mind actually !
    $endgroup$
    – deeppinkwater
    4 hours ago















2












$begingroup$

The number one is the dimension, of course, since two vector spaces over the same field are isomorphic if and only if they have the same dimension.






share|cite|improve this answer









$endgroup$












  • $begingroup$
    Thank you, that's the only one that came to my mind actually !
    $endgroup$
    – deeppinkwater
    4 hours ago













2












2








2





$begingroup$

The number one is the dimension, of course, since two vector spaces over the same field are isomorphic if and only if they have the same dimension.






share|cite|improve this answer









$endgroup$



The number one is the dimension, of course, since two vector spaces over the same field are isomorphic if and only if they have the same dimension.







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered 4 hours ago









José Carlos SantosJosé Carlos Santos

170k23132238




170k23132238











  • $begingroup$
    Thank you, that's the only one that came to my mind actually !
    $endgroup$
    – deeppinkwater
    4 hours ago
















  • $begingroup$
    Thank you, that's the only one that came to my mind actually !
    $endgroup$
    – deeppinkwater
    4 hours ago















$begingroup$
Thank you, that's the only one that came to my mind actually !
$endgroup$
– deeppinkwater
4 hours ago




$begingroup$
Thank you, that's the only one that came to my mind actually !
$endgroup$
– deeppinkwater
4 hours ago

















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%2f3163230%2finvariants-between-two-isomorphic-vector-spaces%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

acmart: Multiple authors: all with same affiliation, one author an additional affiliationHow to Write Names of Multiple Authors with Shared Affiliation in ACM 2017 Template?Multiple authors with different primary affiliation, but same additional affiliationSame affiliation for all authors without extra packagesIOS-Book-Article.cls: one author with multiple affiliationacmart: Shared Author AffiliationMultiple authors with different primary affiliation, but same additional affiliationAuthor affiliation with only 1 authorAdding Multiple Authors with Different Affiliation in LaTeX ArticleLaTeX: Multiple authors stays on same lineHow to Label Multiple Authors with Same DescriptionHow to make two authors use the same affiliationTwo authors with same affiliation on finished front page

How to write “ä” and other umlauts and accented letters in bibliography?Accents in BibTeXSorting references with special characters alphabeticallyUse ae ligature in bibliographyEastern European nameInverted circumflex in BibTexBibTex, non-ascii initials and nameptr fproblems with accent in LatexHow to add a Ø to my bibliography from Jabref?References without accentsTroubles when trying to cite St“omer-Verlet in ”title" field of a bib entryComprehensive list of accented charactersHow to type the letter “i” with two dots (diaeresis) in math mode?Problem with glossary text and accented lettersSpecial character in bibliographyAccented letters, Unicode and LaTeX accentsHow to stop natbib from modifying bibliography styleCitation of a paper with non-standard characters by BibtexWrite accented characters to file using writeHow to group the bibliography alphabetically, if some surnames start with “accented” characters?How can I automatically capitalize significant words in my bibliography?

Problem using RevTeX4-1 with “! Undefined control sequence. @bibitemShut”