# On the Relation Between Quantum Computational Speedup and Retrocausality

@article{Castagnoli2016OnTR, title={On the Relation Between Quantum Computational Speedup and Retrocausality}, author={Giuseppe Castagnoli}, journal={Quanta}, year={2016}, volume={5}, pages={34-52} }

We investigate the reason for the quantum speedup (quantum algorithms require fewer computation steps than their classical counterparts). We extend the representation of the quantum algorithm to the process of setting the problem, namely choosing the function computed by the black box. The initial measurement selects a setting at random, Bob (the problem setter) unitarily changes it into the desired one. With reference to the observer dependent quantum states of relational quantum mechanics…

## 6 Citations

### Completing the physical representation of quantum algorithms explains their computational speedup

- Computer Science
- 2017

An optimal quantum algorithm is a sum over classical histories in each of which Alice knows in advance one of the possible halves of the solution and performs the computation steps necessary to identify the missing half.

### Completing the physical representation of quantum algorithms provides a retrocausal explanation of their speedup

- Computer Science
- 2016

A fundamental justification for the explanation of the speedup is provided and it is shown that it answers the well accepted requirement of the completeness of the physical description of quantum algorithms by just completing the physical representation ofquantum algorithms.

### Completing the Physical Representation of Quantum Algorithms Provides a Quantitative Explanation of Their Computational Speedup

- Computer Science
- 2018

The physical representation of the usual representation of quantum algorithms shows that the number of computation steps required to solve any oracle problem in an optimal quantum way should be that of a classical algorithm endowed with the advanced knowledge of half solution.

### 3D Image Encryption Algorithm Based on Quantum Random Walk and Multidimensional Chaos

- Computer ScienceActa Physica Sinica
- 2022

The blind watermark embedding algorithm based on DCT and SVD is used to embed the watermark information into the encrypted image, so that the receiver can extract theWatermark information and judge whether the image is damaged by attack in the process of transmission according to the integrity of the water Mark, which improves the protection of image information security.

### Quantum Confidentiality Query Protocol Based on Bell State Identity

- Computer ScienceInternational Journal of Theoretical Physics
- 2022

### Effects of initial states on the quantum correlations in the generalized Grover search algorithm*

- PhysicsChinese Physics B
- 2021

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