Question
Asked 17th Oct, 2022

How can we calculate the dimensionality of some new investigated discrete space?

How can we calculate the number of dimensions in a discrete space if we only have a complete scheme of all its points and possible transitions between them (or data about the adjacency of points)? Such a scheme can be very confusing and far from the clear two- or three-dimensional space we know. We can observe it, but it is stochastic and there are no regularities, fractals or the like in its organization. We only have access to an array of points and transitions between them.
Such computations can be resource-intensive, so I am especially looking for algorithms that can quickly approximate the dimensionality of the space based on the available data about the points of the space and their adjacencies.
I would be glad if you could help me navigate in dimensions of spaces in my computer model :-)

All Answers (3)

Anil Kumar Jain
Jain Super Mart
Applications are made with some set of conditions only, you may design or can think your own different algorithm as per need but a perfect answer or any such applications with random choices do not exist. In short from design point of view question is false or not asked as per needs.
Sergey Miroshnikov
Saint Petersburg State University
Thank you for your answer! Did I understand correctly that my question is too general and therefore cannot have a universal answer - an algorithm for all possible cases?
Can I then ask another question: do you know any approaches (algorithms) to calculating dimensionality for discrete space, or can we talk about calculating dimensionality only for linear continuous space?
Sergey Miroshnikov
Saint Petersburg State University
Anil Kumar Jain The description of discrete spaces is found in physical works, e.g. "Discrete spacetime, quantum walks and relativistic wave equations" by Leonard Mlodinow and Todd A. Brun, https://arxiv.org/abs/1802.03910. But I have not seen any attempt to quantify the dimensionality of such spaces. This is exactly what I am looking for.

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Why focus on thermodynamics?
Discussion
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  • Tang SuyeTang Suye
The original manuscript of this article is to answer some questions asked by Zhihu users, here added the second half of the content into the original manuscript, one for sharing, and the other to keep some views written casually, so as not to be lost, it may be useful in the future.
To talk about this problem under the topic of physics is because thermodynamics describes collective behavior and involves all levels. As far as the current situation of thermodynamics is concerned, classical thermodynamics + chemical thermodynamics seems more systematic, but it is not complete.
In comparison, thermodynamics is not as exquisite and rigorous as other theoretical systems of physics, the physical images of many concepts such as entropy, enthalpy and other thermodynamic potentials now are still unclear, and the mathematical transformations, from the perspective of physical meaning, cannot plainly shown what physical contents are transformed, the physical images of many derivatives, differentials, and equations are unclear, for instance, those derivatives, differentials cannot even distinguish between energy transfer and energy conversion.
The way classical thermodynamics is thought is also different from other systems of physics, the "subdivision" of the internal energy is not in place. We all know that the internal energy is the sum of different forms of energy within a given system, since there have different forms, then it should be classified, no, that's a pile. The description method is to see how much comes out through the heat transfer path, how much can come out through the work path, and calculate a total changes, the unique definitions are the parts that can be released in the form of work, called the thermodynamic potentials, when the path changed, one don't know whether they still are.
There is no even a basic classification of the internal energy, how to discuss the conversion between different forms of energy?
For example, a spontaneous chemical reaction, G decreases, S increases, but from the perspective of energy conversion, the answer by a professor of chemistry may not be as good as a liberal arts student who have studied a little in high school and forget most of it, the latter will most likely say that it is chemical energy converted into heat energy, although the terms are not professional, but the meaning of energy conversion is clear. The professors of chemistry know that G decreased, but they don't know what this decreased G turns into, there is no a complete narrative about energy conversion.
In the entire thermodynamic theoretical system, you can hardly find such a sensation, such as delicate, rigorous, physical image clarity, similar to that in the other theoretical systems of physics, and the appeasement philosophy is all over the place.
Statistical physics cannot independently establish equations for the relationships between thermodynamic state functions, relies on thermodynamics in the theoretical system, which also inherited the problems from thermodynamic theory. Statistical physics itself also brings more problems, for instance, statistical physics cannot explain such a process, an ideal gas does work to compress a spring, the internal energy of the ideal gas is converted into the elastic potential energy of the spring. If such simple, realistic problem cannot be explained, what are the use your statistical ensemble, phase spaces, the Poincaré recurrence theorem, mathematical transformations?
The thermodynamic direction maybe currently the last big chance in theoretical physics that can be verified or falsified, because it doesn't face the difficulties in other directions: you can write some dizzying mathematical equations, but maybe a century from now you don't know whether it's right or wrong.
Thermodynamics is the most grand theoretical system in the entire scientific system, a scientific system on natural evolution, although it is not yet complete, and has not yet risen to the level of fundamental theory, which provides a grand narrative of natural evolution, running through all levels.
Newton laws, Maxwell equations, Schrödinger equation, Hamiltonian dynamics, etc., for thermodynamics, that is only one law: the first law of thermodynamics, the law reveals the conservation of energy and conversion relationships of collective behavior at all levels and in all processes, the direction of change that the second law of thermodynamics described now has not been found in the dynamics of physics, will there be? there are some clues but not certain, because there is no corresponding theoretical framework.
The popular view of physicists on the conflict between time inversion symmetry of the fundamental process of dynamics and the second law is all wrong, the errors are: 1, confused the relationship between the fundamental laws, the theme that those dynamical equations discussed is the relation of conservation of energy, which correspond to the first law of thermodynamics, and the time inversion for the first law of thermodynamics is also symmetrical. 2, The symmetry of an equation and the symmetry of a phenomenon are two different concepts, the time inversion symmetry of the energy conservation equation only shows that energy conserve in past, present, and future, it does not explain whether the phenomenon itself is symmetrical in time inversion, the problem that the fundamental dynamic processes themselves are reversible or irreversible cannot be discussed by the equation of conservation of energy.
Have you noticed? in department of chemistry, one have to face the problem of time inversion asymmetry every day, and they also have dynamics, the chemical dynamics of time inversion asymmetry.
On the problem of irreversibility, those seemingly delicate, rigorous, time-inverse symmetrical physical systems are completely powerless, statistical physics is somewhat useful, such as explaining the diffusion phenomenon, calculating the number of collisions, its effective range has been limited by its theoretical postulates, the postulate of an equal probability determines that it is only valid for describing the processes tending to an equal probability distributions. In the framework of statistical physics, there is only one driving force of "change", tending to an equal probability distributions, the question is, the driving forces of "changes" in the real world around us are not only this one.
The second law of thermodynamics indicates that there are two different "dynamics": the physics of time inversion symmetry shows people a world without evolution, and the chemical dynamics of time inversion asymmetry shows us the different situations, whether the latter has universal sense at other levels is still unknown. From astrophysics to macroscopic, at least to the elementary particles level, all observed and confirmed results without exception strongly support the existence for the dynamics which are time inversion asymmetry, will it point to a final ending?
Let's take a look at the different thermodynamics?
The articles linked below show a new theoretical framework for thermodynamics that is different from what you can see in textbooks and other articles, and it also provides a new starting point for the study of a series of major problems.
Can infinitesimals be eliminated from mathematics? (II) (CLOSED)
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  • Ed GerckEd Gerck
Our answer is YES. A new question (at https://www.researchgate.net/post/If_RQ_what_are_the_consequences/1) has been answered affirmatively, confirming the YES answer in this question, with wider evidence in +12 areas.
This question continued the same question from 3 years ago, with the same name, considering new published evidence and results. The previous text of the question maybe useful and is available here:
We now can provably include DDF [1] -- the differentiation of discontinuous functions. This is not shaky, but advances knowledge. The quantum principle of Niels Bohr in physics, "all states at once", meets mathematics and quantum computing.
Without infinitesimals or epsilon-deltas, DDF is possible, allowing quantum computing [1] between discrete states, and a faster FFT [2]. The Problem of Closure was made clear in [1].
Although Weyl training was on these mythical aspects, the infinitesimal transformation and Lie algebra [4], he saw an application of groups in the many-electron atom, which must have a finite number of equations. The discrete Weyl-Heisenberg group comes from these discrete observations, and do not use infinitesimal transformations at all, with finite dimensional representations. Similarly, this is the same as someone trained in infinitesimal calculus, traditional, starts to use rational numbers in calculus, with DDF [1]. The similar previous training applies in both fields, from a "continuous" field to a discrete, quantum field. In that sense, R~Q*; the results are the same formulas -- but now, absolutely accurate.
New results have been made public [1-3], confirming the advantages of the YES answer, since this question was first asked 3 years ago. All computation is revealed to be exact in modular arithmetic, there is NO concept of approximation, no "environmental noise" when using it.
As a consequence of the facts in [1], no one can formalize the field of non-standard analysis in the use of infinitesimals in a consistent and complete way, or Cauchy epsilon-deltas, against [1], although these may have been claimed and chalk spilled.
Some branches of mathematics will have to change. New results are promised in quantum mechanics and quantum computing.
This question is closed, affirming the YES answer.
REFERENCES
[2]
Preprint FT = FFT
[3]

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