cohomologo

6 ms·

1.
by cohomologo 2y ago
Note this is version 2 of the Arxiv posting. The first version claims a proof of Collatz, which appears to be effectively withdrawn by the update.
2.
by cohomologo 2y ago
Physicist here: Just gave it a cursory look, but looks like crank nonsense to me. The paper makes no effort to give any context on what an informaton at a level that physicists would understand.
3.
by cohomologo 3y ago
True, but as someone who works on quantum physics using classical computers and loves to see classical computers simulating increasingly hard quantum problems, these "crushings" were still only done on classical computers in a way
4.
by cohomologo 3y ago
I research QC. Feel free to explain how my skills could be used to meaningfully contribute to the problem of world hunger or renewable energy while also keeping me employed --- going back to college to train in a different field isn't
5.
by cohomologo 3y ago
No, but the quantum groups are making progress towards essentially making 1 logical qubit -- a common scheme uses a square grid of physical qubits, say with size 7x7, 8x8, 9x9, etc.. as a single logical qubit. This may seem like a moving ta
6.
by cohomologo 3y ago
In my experience in QC, I've yet to see many grifters. In fact, many of the people in quantum computing are quite open about the fact that we aren't that close to "useful" quantum computing, that the number of practical
7.
by cohomologo 4y ago
As far as I understand it, either two incommensurate frequencies or the Fibonacci sequence ABAAB… approach produce similar physics. The Fibonacci sequence is easier to simulate numerically on a (classical) computer because there is a recurs
8.
by cohomologo 5y ago
I got lucky with 5 as well: ADIEU BLAST MANOR FANNY CANNA ⬜⬜⬜⬜ ⬜⬜⬜⬜ ⬜⬜⬜ ⬜⬜
9.
by cohomologo 7y ago
With double exponential growth, “it looks like nothing is happening, nothing is happening, and then whoops, suddenly you’re in a different world,” Neven said. This is just a clever way to spin the fact that we are experiencing growth much s
10.
by cohomologo 9y ago
Is "beyond a shadow of doubt" the standard of proof we need to take action? I would advocate for an actuarial standard. (i.e. estimate the probabilities and costs/benefits of various outcomes and take the path with the best e
11.
by cohomologo 9y ago
From the ARCH foundation FAQ: Beyond the laser based digital layer there may also be layers that require the ability to detect and decode molecular, atomic scale or subatomic scale (quantum or holographic) information. We can already encode
12.
by cohomologo 9y ago
I think you've got that last part backwards. When you have constituents with binding energy, that reduces the total energy of the system and reduces the mass. So it seems that the mass of the proton is quark mass + gluon kinetic energy
13.
by cohomologo 9y ago
It's pretty easy. If your computer has enough ram to store a size 2^16 length complex vector (which is 2^20 bytes, or 1MB) than you can open up an ipython notebook and write code to apply quantum gates to it with no problem. The proble
14.
by cohomologo 9y ago
I think it's more like a 6 bit number, and probably not very fast at all...
15.
by cohomologo 9y ago
The Google group in Santa Barbara is building to a 49-qubit computer. If I understand correctly, it'll be interesting for understanding how you calibrate your quantum machine and validate that it is doing what it is supposed to. The al
16.
by cohomologo 9y ago
Not any given quantum computer -- Scott Aaronson debunks the D-Wave "quantum" annealers that aren't actually shown to be harnessing the quantum power. IBM's machine by contrast is a genuine quantum computer -- the kind S
17.
by cohomologo 9y ago
The point where it gets interesting for realistic physics and chemistry applications is around 100 (error-corrected) logical qubits and 10^8 coherent operations, see for example https://arxiv.org/abs/1510.03859 . The er
18.
by cohomologo 9y ago
> As it does, its power to make predictions of unknown objects should grow, until we've reached the limit of our current instruments' ability to observe. Well that's kind of the problem already. For the objects that are in
19.
by cohomologo 10y ago
The symmetry breaking should be thought of as a phase transition that occurs as the temperature of the universe changes, like liquid freezing and becoming ice. The universe was initially very hot, but rapidly cooled down as it expanded and
20.
by cohomologo 10y ago
In fact, treating particles like vortices and vice versa is a good analogy that can be made more precise with an idea called particle-vortex duality. The basic idea is that you make a change of variables so that the vortices of the old vari
21.
by cohomologo 10y ago
Nope. Like in the ground state of the hydrogen atom, the ground state of the quantum harmonic oscillator has the wave function spread out in a sphere, and this wave function stays constant in time. Almost all quantum systems do something li
22.
by cohomologo 10y ago
Electrons do not orbit atomic nuclei in the quantum description of atoms. Instead, in the lowest energy state the electron wave function is spread out in a sphere around the nucleus, and this wave function stays constant in time. Almost all
23.
by cohomologo 10y ago
The connection with quantum information (the theme of research at Station Q) is through the many-body localization (MBL) aspect of this system. These are phases that store quantum information at finite temperature. Normal quantum systems th
24.
by cohomologo 10y ago
Physicist here with some context: The systems considered here have periodic drives (in the article, "Floquet"). This means that time-translational symmetry is already partially broken. The system is only the same after waiting tim
25.
by cohomologo 10y ago
Knot theory is still quite popular with physicists of certain sorts, such as condensed matter physicists that study "topological phases" - a popular account that I like can be found here: https://www-thphys.physics.ox.a
26.
by cohomologo 10y ago
Cool, thanks for the info. I enjoyed playing with Quirk, it's very nice.
27.
by cohomologo 10y ago
I've never seen a physics book that treats this using the zeta function, except popular articles that try to present this calculation as mysterious. In practice, in my QFT class we needed to compute the sum lim \epsilon -> 0+ ( \sum
28.
by cohomologo 10y ago
There is a much simpler mathematical treatment of this series that appeared in my class on quantum field theory in the computation of the vacuum energy. In that case, the series was treated as lim \epsilon -> 0+ ( \sum_{n=1}^\infty n e^{
29.
by cohomologo 10y ago
Could you help us understand what the limiting factor in these simulations are? By memory considerations alone, a N-qubit wavefunction (using 64-bit floats) uses 2^(N+4) bytes, and a N-qubit unitary operator uses 2^(2N+4) bytes. If you use
30.
Supervised Learning with Quantum-Inspired Tensor Networks(arxiv.org)
2 points by cohomologo 10y ago|0 comments

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