The Two-State Vector Formalism

In summary: It allows for an objective reality and a clear picture of causation.In summary, the conversation discussed the Two-state vector formalism and whether the universe is probabilistic or determined. The formalism is a re-packaging of the Copenhagen interpretation and is not considered a real attempt at interpretation. There seems to be disagreement on whether the formalism implies determinism or indeterminism. However, the concept of indeterministic consistent histories was considered to be the most logical explanation for quantum mechanics.
  • #1
Hybrid
30
2
 
Physics news on Phys.org
  • #2
Hybrid said:
Within Two-state vector formalism is the universe probabilistic or determined?
I have read into this interpretation, but I cannot figure out which.
Thanks guys

https://en.wikipedia.org/wiki/Two-state_vector_formalism
http://www.tau.ac.il/~yakir/yahp/yh165.pdf
http://www.tau.ac.il/~vaidman/lvhp/m108.pdf
http://arxiv.org/pdf/0706.1347v1.pdf
http://arxiv.org/pdf/quant-ph/0105101v2.pdf
http://arxiv.org/pdf/1406.6382v1.pdf
http://philsci-archive.pitt.edu/4396/1/vaidman_paper_jb_3rd_edit.pdf

Well, in your second reference, equation 13.9 clearly gives probabilities for measurement results.
 
  • Like
Likes Hybrid
  • #3
stevendaryl said:
Well, in your second reference, equation 13.9 clearly gives probabilities for measurement results.

Thanks I picked up on that as well, however it's irritating to me that the author's didn't just come out and state if it's a realist interpretation or indeterminate. Although it does seem as though retro-causality would imply in-determinism.
 
  • #4
The universe is deterministic according to the TSVF. Both the forwards and backwards evolving wave function evolve in accord with deterministic laws. Since both wave functions come together to constitute reality, reality will "seem" probabilistic if you don't know the backwards evolving wave function.
 
  • #5
Hybrid said:
Thanks I picked up on that as well, however it's irritating to me that the author's didn't just come out and state if it's a realist interpretation or indeterminate. Although it does seem as though retro-causality would imply in-determinism.

As I understand it, the two-state vector formalism is Copenhagen. The formalism is not a new interpretation, but a re-packaging of Copenhagen to make certain calculations more intuitive. In particular, the formalism is not an interpretation because it does not aim to solve (or dissolve) the measurement problem, unlike real attempts at interpretation such as MWI, BM and Consistent Histories.
 
  • #6
Agrippa said:
The universe is deterministic according to the TSVF. Both the forwards and backwards evolving wave function evolve in accord with deterministic laws. Since both wave functions come together to constitute reality, reality will "seem" probabilistic if you don't know the backwards evolving wave function.

Yes, and I'm aware of this as I've already looked it, although their view of determinism isn't so cut and dry, and leaves much to be desired. They used weak measurements to come to this conclusion which are questionable at best. (http://motls.blogspot.com/2012/09/pseudoscience-hiding-behind-weak.html)

Also I found this tidbit of information perusing around the internet interesting -

"Charles Bennett of IBM’s research laboratories in Yorktown Heights, New York, a specialist on quantum information theory, is not convinced. For a start, he sees the TSVF as only one way of looking at the results. “People in quantum foundations are often so wedded to their own interpretation or formalism that they say it is the only reasonable one, when in fact quantum mechanics admits multiple interpretations, which except for a few outliers are entirely equivalent to one another. The differences are aesthetic and philosophical, not scientific.”

Bennett believes that the findings can be interpreted without any apparent ‘backwards causation’, so that the authors are erecting a straw man. “To make their straw man seem stronger, they use language that in my opinion obscures the crucial difference between communication and correlation. They say that the initial weak measurement outcomes anticipate the experimenter's future choice but that doing so causes no violation of causality because the anticipation is encrypted.” But he thinks this is a bit like an experiment in quantum cryptography in which the sender sends the receiver the decryption key before sending (or even deciding on) the message, and then claims that the key is somehow an ‘anticipation’ of the message. With this in mind, it is not clear whether even an experiment will resolve the issue, since it would come down to a matter of how to interpret the results."

Point being that this is not actual determinism, it's still inherently indeterministic.

atyy said:
As I understand it, the two-state vector formalism is Copenhagen. The formalism is not a new interpretation, but a re-packaging of Copenhagen to make certain calculations more intuitive. In particular, the formalism is not an interpretation because it does not aim to solve (or dissolve) the measurement problem, unlike real attempts at interpretation such as MWI, BM and Consistent Histories.

Yes, I agree.

After evaluating all the interpretations of quantum mechanics indeterministic consistent histories makes the most sense of things.
 
Last edited:

1. What is the Two-State Vector Formalism?

The Two-State Vector Formalism (TSVF) is a quantum mechanical framework that describes the evolution of a quantum system by using two state vectors instead of a single wave function. It was developed by Yakir Aharonov and Lev Vaidman in the 1990s as an alternative to the traditional description of quantum mechanics using the Schrödinger equation.

2. How does the TSVF differ from the Schrödinger equation?

In the TSVF, the two state vectors represent the initial state and final state of a quantum system, and the evolution between these states is governed by a time-symmetric equation known as the TSVF equation. This differs from the Schrödinger equation, which describes the evolution of a single state vector over time.

3. What are the advantages of using the TSVF?

The TSVF allows for a more intuitive understanding of the quantum system, as it tracks the evolution of two distinct states rather than a single wave function. It also provides a more complete description of quantum measurements, as it accounts for both the pre- and post-measurement states of a system.

4. Can the TSVF be applied to all quantum systems?

While the TSVF has been successfully applied to various quantum systems, it is not a universal framework and may not be applicable to all cases. Its use is primarily limited to systems with a finite number of states and a discrete spectrum of energy levels.

5. Are there any controversies surrounding the TSVF?

There is ongoing debate and discussion among scientists about the validity and usefulness of the TSVF. Some argue that it is not a complete description of quantum mechanics and has limitations, while others believe it provides a valuable alternative perspective on the behavior of quantum systems.

Similar threads

I Two-State Vector Formalism - I like it
    • Quantum Physics
Replies
1
Views
867
A Yakir Aharonov's time-symmetric formulation of quantum mechanics
    • Quantum Interpretations and Foundations
Replies
7
Views
712
Prospects of spin foam formalism in loop quantum gravity [Alexandrov, Roche]
    • Beyond the Standard Models
Replies
9
Views
6K

Hot Threads

Recent Insights

Back
Top