Postselection

In probability theory, to postselect is to condition a probability space upon the occurrence of a given event. In symbols, once we postselect for an event $E$ , the probability of some other event $F$ changes from $Pr [F]$ to the conditional probability $Pr [F | E]$ .

For a discrete probability space, $Pr [F | E] = \frac{Pr [F \cap E]}{Pr [E]}$ , and thus we require that $Pr [E]$ be strictly positive in order for the postselection to be well-defined.

See also PostBQP, a complexity class defined with postselection. Using postselection it seems quantum Turing machines are much more powerful: Scott Aaronson proved^[1]^[2] PostBQP is equal to PP.

Some quantum experiments^[3] use post-selection after the experiment as a replacement for communication during the experiment, by post-selecting the communicated value into a constant.

References

^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).

P ≟ NP

This theoretical computer science–related article is a stub. You can help Wikipedia by expanding it.

Stub icon

This probability-related article is a stub. You can help Wikipedia by expanding it.

[PostBQP_=_PP-1] Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).

[2] Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).

[Hensen_et_al.-3] Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).

[1]

[2]

[3]

Postselection

References

Navigation menu

Search