Do Tensor Product Properties Hold in Infinite Dimensional Hilbert Spaces?

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SUMMARY

The properties of tensor products in infinite dimensional Hilbert spaces are confirmed to hold true. Specifically, the equations \((\hat{A}_1 \otimes \hat{A}_2)^{-1}=\hat{A}^{-1}_1 \otimes \hat{A}^{-1}_2\), \((\hat{A}_1 \otimes \hat{A}_2)^{\dagger}=\hat{A}^{\dagger}_1 \otimes \hat{A}^{\dagger}_2\), and others are valid under appropriate conditions. The discussion references "Lectures on von Neumann Algebras" by Serban Stratila and Laszlo Zsido as a key resource for understanding these properties, along with the more complex treatment found in "Operator Algebras and Quantum Statistical Mechanics" by Bratteli and Robinson.

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  • Understanding of infinite dimensional Hilbert spaces
  • Familiarity with operator theory
  • Knowledge of tensor products in functional analysis
  • Basic concepts of quantum mechanics related to operators
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  • Study "Lectures on von Neumann Algebras" by Serban Stratila and Laszlo Zsido for foundational concepts
  • Explore "Operator Algebras and Quantum Statistical Mechanics" by Bratteli and Robinson for advanced applications
  • Research the properties of tensor products in functional analysis
  • Learn about the implications of operator theory in quantum mechanics
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LagrangeEuler
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Is this correct in infinite dimensional Hilbert spaces?
## (\hat{A}_1 \otimes \hat{A}_2)^{-1}=\hat{A}^{-1}_1 \otimes \hat{A}^{-1}_2 ##
## (\hat{A}_1 \otimes \hat{A}_2)^{\dagger}=\hat{A}^{\dagger}_1 \otimes \hat{A}^{\dagger}_2 ##
## (\hat{A}_1 +\hat{A}_2) \otimes \hat{A}_3=(\hat{A}_1 \otimes \hat{A}_2)+(\hat{A}_2 \otimes \hat{A}_3) ##
## \hat{A}_1 \otimes (\hat{A}_2+\hat{A}_3)=(\hat{A}_1 \otimes \hat{A}_2)+(\hat{A}_1 \otimes \hat{A}_3) ##
## \hat{1} \otimes \hat{1}=\hat{1} ##
## (\hat{A}_1 \otimes 0)=(0 \otimes \hat{A}_2)=0 ##
Can you tell me a book where I can see this properties. I found this only for operators which acts in finite dimensional Hilbert spaces.
 
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Your question belongs to the part of mathematics usually discussed within "Operators theory". But here is essentially the positive answer to your questions (with somewhat different notation) - provided appropriate care is being taken:

stratila58.jpg


Taken from "Lectures on von Neumann Algebras" by Serban Stratila and Laszlo Zsido, Abacus Press 1975. You can also find it in online Bratteli and Robinson book "Operator algebras and quantum statistical mechanics", Vol. 1, but there it is more complicated as tensor product of not just two but a family of Hilbert spaces is being considered.
 

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