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Symmetric groups possess a well-known bijection between conjugacy classes and irreducible representations. More precisely, both sets are indexed by Young diagrams.

Question: To what extent is this bijection natural?

This question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. E.g. properties like: identity class is mapped to trivial irreps...

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that no natural bijection between the two sets is known (and may not exist at all).

MathOverflow has already several discussions around the subject, however they are different from the present question. A few of them are listed below.

Bijection between irreducible representations and conjugacy classes of finite groupsBijection between irreducible representations and conjugacy classes of finite groups discusses bijections for general groups.

The symmetric groups are not the only groups with a "natural" bijection. Some examples are collected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classesG/[G,G], irreps and conjugacy classes, Duality between conjugacy classes and irreducible characters for finite monoids?Duality between conjugacy classes and irreducible characters for finite monoids?, among others.

Conjugacy classes and irreps have many similar properties. However, in general, they do not fit each other exactly: Action of Out(G) on both setsAction of Out(G) on both sets, "reality properties" (Are there “real” vs. “quaternionic” conjugacy classes in finite groups?Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?).

Symmetric groups possess a well-known bijection between conjugacy classes and irreducible representations. More precisely, both sets are indexed by Young diagrams.

Question: To what extent is this bijection natural?

This question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. E.g. properties like: identity class is mapped to trivial irreps...

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that no natural bijection between the two sets is known (and may not exist at all).

MathOverflow has already several discussions around the subject, however they are different from the present question. A few of them are listed below.

Bijection between irreducible representations and conjugacy classes of finite groups discusses bijections for general groups.

The symmetric groups are not the only groups with a "natural" bijection. Some examples are collected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes, Duality between conjugacy classes and irreducible characters for finite monoids?, among others.

Conjugacy classes and irreps have many similar properties. However, in general, they do not fit each other exactly: Action of Out(G) on both sets, "reality properties" (Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?).

Symmetric groups possess a well-known bijection between conjugacy classes and irreducible representations. More precisely, both sets are indexed by Young diagrams.

Question: To what extent is this bijection natural?

This question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. E.g. properties like: identity class is mapped to trivial irreps...

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that no natural bijection between the two sets is known (and may not exist at all).

MathOverflow has already several discussions around the subject, however they are different from the present question. A few of them are listed below.

Bijection between irreducible representations and conjugacy classes of finite groups discusses bijections for general groups.

The symmetric groups are not the only groups with a "natural" bijection. Some examples are collected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes, Duality between conjugacy classes and irreducible characters for finite monoids?, among others.

Conjugacy classes and irreps have many similar properties. However, in general, they do not fit each other exactly: Action of Out(G) on both sets, "reality properties" (Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?).

removed tag 'u'; a little editing
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Ricardo Andrade
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What is natural about the well-known bijection between conjugacy classes and irreps of a symmetric group?

Symmetric group hasgroups possess a well-known bijection between conjugacy classes and irreducible representations. I.e. More precisely, both sets are indexed by Young diagrams.

Question: To what extent is this bijection is natural  ?

QuestionThis question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. (EE.g. properties like: identity class is mapped to trivial irreps... ).

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that it there is no natural bijection between the two sets isis known/  (and may be not existsexist at all).

MathoverflowMathOverflow has already several discussions around the subject, however, they are different from the present question. A few of them are listed below.

Bijection between irreducible representations and conjugacy classes of finite groups,

(Discuss about bijection discusses bijections for GENERALgeneral groups).

Symmetric group isThe symmetric groups are not the only groupgroups with a "natural" bijection, some. Some examples are colloectedcollected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes,  Duality between conjugacy classes and irreducible characters for finite monoids?, ..among others.

Conjugacy classes and irreps have many similar similar properties, however. However, in general, they do tonot fit each other exactly: Action of Out(G) on both sets, "reality properties" (  Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?).

What is natural about well-known bijection between conjugacy classes and irreps of symmetric group?

Symmetric group has well-known bijection between conjugacy classes and irreducible representations. I.e. both sets are indexed by Young diagrams.

Question: To what extent this bijection is natural  ?

Question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. (E.g. properties like: identity class is mapped to trivial irreps... ).

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that it there is no natural bijection between the two sets is known/(and may be not exists at all).

Mathoverflow has already several discussions around the subject, however, they are different from the present question.

Bijection between irreducible representations and conjugacy classes of finite groups,

(Discuss about bijection for GENERAL groups).

Symmetric group is not the only group with "natural" bijection, some examples are colloected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes,Duality between conjugacy classes and irreducible characters for finite monoids?, ...

Conjugacy classes and irreps have many similar properties, however, in general they do to fit each other exactly: Action of Out(G) on both sets, "reality properties" (  Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?

What is natural about the well-known bijection between conjugacy classes and irreps of a symmetric group?

Symmetric groups possess a well-known bijection between conjugacy classes and irreducible representations. More precisely, both sets are indexed by Young diagrams.

Question: To what extent is this bijection natural?

This question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. E.g. properties like: identity class is mapped to trivial irreps...

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that no natural bijection between the two sets is known  (and may not exist at all).

MathOverflow has already several discussions around the subject, however they are different from the present question. A few of them are listed below.

Bijection between irreducible representations and conjugacy classes of finite groups discusses bijections for general groups.

The symmetric groups are not the only groups with a "natural" bijection. Some examples are collected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes,  Duality between conjugacy classes and irreducible characters for finite monoids?, among others.

Conjugacy classes and irreps have many similar properties. However, in general, they do not fit each other exactly: Action of Out(G) on both sets, "reality properties" (Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?).

added 849 characters in body; edited tags
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Alexander Chervov
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Symmetric group has well-known bijection between conjugacy classes and irreducible representations. I.e. both sets are indexed by Young diagrams.

Question: To what extent this bijection is natural ?

Question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. (E.g. properties like: identity class is mapped to trivial irreps... ).

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that it there is no natural bijection between the two sets is known/(and may be not exists at all).

Mathoverflow has already several discussions around the subject, however, they are different from the present question.

Bijection between irreducible representations and conjugacy classes of finite groups,

(Discuss about bijection for GENERAL groups).

Symmetric group is not the only group with "natural" bijection, some examples are colloected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes,Duality between conjugacy classes and irreducible characters for finite monoids?, ...

Conjugacy classes and irreps have many similar properties, however, in general they do to fit each other exactly: Action of Out(G) on both sets, "reality properties" ( Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?

Symmetric group has well-known bijection between conjugacy classes and irreducible representations. I.e. both sets are indexed by Young diagrams.

Question: To what extent this bijection is natural ?

Question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. (E.g. properties like: identity class is mapped to trivial irreps... ).

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that it there is no natural bijection between the two sets is known/(and may be not exists at all).

Mathoverflow has already several discussions around the subject,

Bijection between irreducible representations and conjugacy classes of finite groups,

Symmetric group is not the only group with "natural" bijection, some examples are colloected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes,Duality between conjugacy classes and irreducible characters for finite monoids?, ...

Symmetric group has well-known bijection between conjugacy classes and irreducible representations. I.e. both sets are indexed by Young diagrams.

Question: To what extent this bijection is natural ?

Question is somewhat informal, however I hope it can be left in such a form. One of the ways to make it formal is to ask about the properties which distinguish the bijection above among all bijections between the two sets. (E.g. properties like: identity class is mapped to trivial irreps... ).

Background:

It is very standard material that for any finite group the number of conjugacy classes and irreps is the same, however it is striking that it there is no natural bijection between the two sets is known/(and may be not exists at all).

Mathoverflow has already several discussions around the subject, however, they are different from the present question.

Bijection between irreducible representations and conjugacy classes of finite groups,

(Discuss about bijection for GENERAL groups).

Symmetric group is not the only group with "natural" bijection, some examples are colloected here: Examples of finite groups with “good” bijection(s) between conjugacy classes and irreducible representations?

Related questions: G/[G,G], irreps and conjugacy classes,Duality between conjugacy classes and irreducible characters for finite monoids?, ...

Conjugacy classes and irreps have many similar properties, however, in general they do to fit each other exactly: Action of Out(G) on both sets, "reality properties" ( Are there “real” vs. “quaternionic” conjugacy classes in finite groups?, If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true ?

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Alexander Chervov
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