Recent content by Agrippa

Fair enough. The main questions here have transformed thanks to the feedback. In my original post, I asked two questions: 1. Are current quantum computers restricted to feedforward networks? 2. Are quantum computers restricted in principle to feedforward networks? atyy answered both questions...

Above I distinguished what I take to be the three possible ways that a quantum computer could realize feedback connectivity. And I argued that category 3 (superpositions of classical feedback) is the truly interesting one, since the feedback processing is fully in the computer itself (unlike...

I think the distinction made in my previous post helps here, we can distinguish three types of quantum feedback connectivity: 1) measurement-based (measurement outcomes are also input) 2) coherent feedback (separable quantum systems simulate classical feedback) 3) superpositions of classical...

Thanks, those are extremely helpful links! They seem to suggest that there are two types of "feedback" processes in quantum computation: 1) Measurement based feedback: The quantum system takes input, evolves, then is measured... the experimenter then uses the measurement outcome as new input...

Theoretically you can, because both type of networks are universal function approximators. But my question is not about what is theoretically possible, it is about what is physically possible, hence why I post this in quantum physics thread. Unfolding ("unrolling") typically requires that the...

That doesn't seem correct. For example, here is a simple classical circuit with a feedback loop: http://bibl.ica.jku.at/dc/build/html/sequentiallogic/sequentiallogic.html#feedback-loops Classical computers are therefore not typically feedforward. But I'm yet to see any quantum computer...

Thanks! I understand the difficulty in defining "quantum computer", but I think finding an answer to my question would help with this. I am asking the question for any quantum computer, whether gate based, analogue, or measurement based. I am asking both for already built and merely physically...

Hi! I am trying to understand how advanced quantum computers have in fact become as well as how advanced they can in principle become. To probe these issues, I am asking the group whether or not quantum computers are restricted to feedforward processing, both currently and in principle? Here is...

Does the attached look correct as an implementation of node A? To create a node for C NAND C, I had to split C into C1 and C2, and I also used three intermediary nodes (I1, I2 and I3).

Thanks, this is helpful! My question is really about the implementations of these rules in the kind of system defined by the software I linked to. We can express the rules as a truth table (as in my first link), or we can express the rules by logic operations on inputs (as you have), but how do...

Sorry, here's the link: http://integratedinformationtheory.org/calculate.html I don't see the relevant implementation on wiki - I need to do it with a set of binary nodes that each can be defined as a certain sort of logic gate. Any suggestions appreciated.

Hi, I'm wondering about the Fredkin gate (controlled swap) gate, which is defined by the truth table on p54 here. I'm trying to implement it in a simple feedback network that takes the form of what can be input into this software: integratedinformationtheory.org/calculate. Any pointers would be...

p.s. this thread concerns the master equation for Penrose-Diosi collapse (as opposed to, for example, the state vector evolution equation for Penrose-Diosi collapse). It is PhysForum editors that keep changing the title from "Master equation for..." to the slightly less sexy "Mastering this...

I'm trying to understand equation 209 on page 81 here: https://arxiv.org/pdf/1204.4325.pdf Here's what I understand so far: - We are to imagine a system in a superposition of |X> and |X'>, where these describe distinct particle configurations. - On the RHS of the eqn, the first term is...

Perhaps it's more correct to say: If unitary Schroedinger evolution is the only evolution and realism is true, then MWI is required. (Bohmian mechanics keeps both realism and unitary Schroedinger evolution, but adds additional variables and dynamics in the form of the guiding equation). (QBism...