Irreducible representations of SL(2,C)?

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Discussion Overview

The discussion centers around the definition and representations of the group SL(2,C), particularly focusing on its irreducible representations. Participants explore various definitions and interpretations of SL(2,C) as it relates to linear transformations and matrix properties.

Discussion Character

  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant notes that SL(2,C) is defined by physicists as the group of 2x2 complex matrices with determinant equal to 1, questioning if this is the only representation.
  • Another participant suggests verifying the definition through various documents, emphasizing that special groups typically have unit determinants.
  • A different participant references the groupprops website, stating that SL(2,C) can also be defined as the group of linear transformations on 2-D complex space that preserves oriented areas.
  • Another contribution defines SL(2,C) as a subgroup of GL(2,C), requiring that the endomorphisms of C2 have a matrix with determinant equal to 1 in the standard basis.

Areas of Agreement / Disagreement

Participants present multiple definitions and interpretations of SL(2,C), indicating that there is no consensus on a singular definition or representation. The discussion remains unresolved regarding the formal definition and the nature of irreducible representations.

Contextual Notes

Participants reference different sources and definitions, highlighting potential variations in understanding the concept of SL(2,C). There is an implicit acknowledgment of the complexity and nuance in defining the group and its representations.

pellman
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The group of SL(2,C) is sometimes defined (by physicists) as the group of 2 X 2 complex matrices of determinant = 1. But then we can talk about other representations of SL(2,C). So apparently the set of 2 X 2 complex matrices of determinant = 1 is but one representation of SL(2,C). If so, what then is the more formal definition of SL(2,C) ? And what does another irreducible representation or SL(2,C) look like?
 
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Hey pellman.

I think if you had doubts then you should check the appendix of the document or look for documents that confirm what the definition is across documents and departments.

Usually special groups have unit determinants.
 
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If we believe the groupprops website, SL(2,C) is defined as the set of matrices that has been mentioned. http://groupprops.subwiki.org/wiki/Special_linear_group:SL(2,C) According to the Wikipedia, you could also defined it as the group of linear transformations on 2-D complex space that preserves oriented areas.
 
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You can define it as the subgroup of GL(2,C) by requiring that the endomorphisms of C2 have a matrix of determinant = 1 in the standard basis of C2.
 
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thanks, guys
 

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