Questions tagged [unified-theories]
The unified-theories tag has no usage guidance.
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Unification of Interactions
It has been asked before but with a different aim, and was answered mathematically, while I look for a practical understanding of it. If the Four Foundamental Forces were unified in the first instants ...
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What order did the particles of nature appear in?
in the epochs of the very early universe, the different forces separated from each other in succession. if this is true then at one point there was an electroweak force. and before that, there was the ...
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Is Gravity still considered to be part of the "Superforce" which existed at the instant of the "Big Bang"
My limited understanding of the Big Bang is that all the Fundemental Forces (Electromagnetic, Weak Nuclear, Strong Nuclear and Gravity) were originally part of a "Superforce." As the universe cooled ...
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Are there approaches to show that GR and QFT actually are unifable (without looking for a concrete ToE formalism)?
In mathematics, you can show that some problems are unprovable or have no solution at all and you also have the tool of proof by contradiciton, and similar. But is any of this also applied in physics ...
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Why is gravity such a unique force?
My knowledge on this particular field of physics is very sketchy, but I frequently hear of a theoretical "graviton", the quantum of the gravitational field. So I guess most physicists' assumption is ...
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QED impact on Unified Field Theory [closed]
how did the development of quantum electrodynamics impact the development of modern unified field theories?
and did any other theories have more significant impact?
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Would there be a force carrier particle in the unified field theory?
So from what I understand, each fundamental force (with the exception of gravity unless you count the hypothetical graviton) has a force carrier particle that mediates the force. Does that mean if the ...
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Is a unified theory encompassing all types of physics possible? [closed]
According to the cGh cube, a theory of everything should incorporate quantum mechanics, relativity and gravity. It should also include the other 3 forces to be unified to a single force. However, how ...
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Question about $E_8$ symmetry breaking and hypercharge formula
Most $E_8$ gauge theories follow this breaking chain:
$$E_8 \rightarrow E_6 \times SU(3)_{Gen}.$$
How does the $E_6 \times SU(3)$ group break down through $SO(10)$, the Pati-Salam Model or the Minimal ...
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Are standard QFT and general relativity contradictory?
My professors say it's only a matter of finding the right mathematical formalism to unite GR and QFT, and that new physics can only possibly be found on extremely high energies and small scales.
they ...
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How does Garrett Lisi's $E_8$ Theory contain the Higgs Boson and Graviton?
How does Garrett Lisi's "Exceptionally Simple Theory of Everything" contain the Higgs Boson and Graviton? Let's say that $E_8$ breaks down like this:
$$E_8 \rightarrow E_6 \times SU(3).$$
...
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New theory for unifying general relativity and quantum mechanics [closed]
The media is currently reporting on a new idea in theoretical physics, developed by the group of professor Jonathan Oppenheim, to unify general relativity with quantum theory. The novel idea is not to ...
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Why did Kaluza need to invent a new theory to unify general relativity and electromagnetism?
Wikipedia (and many other sources) say that by extending the number of spacetime dimensions from four to five, Kaluza–Klein theory unifies general relativity and electromagnetism into a single theory. ...
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What is Eric Weinstein's Geometric Unity theory? [closed]
I can usually follow the basic ideas of a theory, but Weinstein's Geometric Unity theory is completely incomprehensible to me. It leads me to suspect that it is high level crackpottery, but he seems ...
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How did Einstein plan to Unify Electromagnetism and Gravity?
I'm asking the question on this site because I'm more concerned with the physics and philosophy of unification than historical details
I know that Einsteins description of gravity includes curvature ...
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Are mass and charge manifistations of the same thing?
Even though mass and charge are two different physical properties of matter, have there been any attempts at unifying them? say, by defining a physical property of matter such that mass and charge are ...
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Was the Michelson & Morely experiment ever valid? [closed]
One of the key predecessors to Einstein's Relativity was another theory having to do with an "Aether" material. This substance was supposed to be the substrate that the universe is built ...
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Spontaneous symmetry breaking in $SU(5)$ GUT?
At the end of this video lecture about grand unified theories, Prof. Susskind explains that there should be some kind of an additional Higgs mechanism at work, to break the symmetry between the $SU(2)$...
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Is there a "unification" explanation of why the mixed gauge-gravitational anomaly cancels in the standard model?
Quoting the Review of Particle Physics (93.2.3):
all representations of SO(10) are anomaly free in four dimensions... the absence of anomalies in ... a SM generation can be viewed as deriving from ...
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Should 4 fundamental forces really be 3 because of electroweak unification?
I read @ http://www.particleadventure.org/
Physicists concluded that, in fact, the weak
and electromagnetic forces have essentially
equal strengths. This is because the strength
of the interaction ...
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Is a QFT always an EFT coming from something deeper?
(I have already read this post but my question is different)
Reading Ch. 12 of Weinberg's Quantum Field Theory Vol. 1, he states that all realistic (interacting) QFTs are now believed to be EFT of ...
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What are the constraints on a quantum gravity theory? [duplicate]
My question is: what are the main constraints or challenges that prevent us from finding a consistent and complete theory of quantum gravity? Are they conceptual, mathematical, physical, or ...
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Limits to the complexity of a fundamental theory
There are examples in physics in which a simple law results from an immeasurably more complicated set of underlying interactions. Consider Hooke's law, for instance: there is a very simple equation ...
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Is the quest for a theory unifying gravity and quantum mechanics just wishful thinking? [closed]
What is the basis of the believe that there should be a unified theory which simultaneously gives quantum physics (the regime small things moving very fast) and gravity (the regime of big things ...
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Is the big bang (BB) correctly summarized as a sequence of symmetry-breaking events? [closed]
Please take this as a serious question from a curious yet deeply underinformed lover of this universe. This is more of a basic question concerning the overall mechanics of the transition stages from ...
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Could the low Higgs mass be relevant to the unification of the (weak) nuclear force and gravity?
I found in a paragraph in a research paper (although it was talking about something else) the statement: that it is possible to unite the weak nuclear force and gravity, but that requires that:
Both ...
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Why are extra dimensions necessary?
Some theories have more than 4 dimensions of spacetime. But we only observe 4 spacetime dimensions in the real world, cf. e.g. this Phys.SE post.
Why are the theories (e.g. string theory) that ...
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Heisenberg's Unified Field Theory
While searching in the Internet, I came to know about Werner Heisenberg's attempt to obtain an Unified Field Theory (see the book Introduction to Unified Field Theory of Elementary Particles). But ...
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Could the particles of the standard model be states of a smaller set of particles?
The standard model describes the particle's initial zoo into a smaller set. If I am not wrong quarks were proposed as a solution even before being detected. Is there any reason why we could not ...
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How do gravity and the quantum co-exist? [duplicate]
In my opinion, the biggest unsolved problem in fundamental physics is how gravity and the quantum will be made to coexist within the same theory. The problem is that quantum physics and general ...
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How Existence Of Matter Is Possible Inside The Black Hole? [closed]
According to Chronology of the universe, origin of the universe initiated as per below sequence:
Big bang (at 0 sec) occurs in the black hole (10^-35 m in size, Planck Length) at the center of the ...
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Which unification theories would require WEP violation?
I was just reading this article about how the weak equivalence principle was recently confirmed up to one part in $10^{15}$, for two metal alloys orbiting Earth.
Are there theories that expect the WEP ...
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Is String Theory actually the supreme theory of Physics that can unite the 'Theory of the Big' and the 'Theory of the Small'? [duplicate]
As Dr. Michio Kaku says, that in the current state of Physics, we have the 'Theory of the Big' that is black holes, the Big Bang, cosmology, astrophysics on one hand and the 'Theory of the Small' that ...
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What is a good non-technical introduction to theories of everything?
I'm not a physicist but I'm interested in unified theories, and I do not know how to start learning about it. What would be a good book to read to start learning about this topic?
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What are the differences between electroweak interactions before and after unification?
I am very confused by this point, although its mathematical description is not hard. I still cannot see how these two theories are "unified", which term in lagrangian indicates this ...
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What does it mean to take GR and QM "together"?
From the "Theory of Everything" Wikipedia article (first paragraph):
Over the past few centuries, two theoretical frameworks have been developed that, together, most closely resemble a TOE. ...
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What is the shortest form way to fully describe the way our universse functions? [closed]
Let's say we wanted to explain to some alien living in another universe with different laws of physics to how our universe worked, what is the shortest way of doing this?
A different way of looking at ...
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Experiments and theory [closed]
Sometimes when the data from experiments disagree with a theory which was supposed to describe the experiment we say:
"This theory works well for some range of variables but there are some ...
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Why did Kaluza-Klein need an additional dimension? [closed]
Why did Kaluza-Klein need an additional dimension and not just treat the fourth dimension as a description of both time and space?
Assume that you can exchange the time dimension to a space dimension ...
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What Data Set(s) Would Be Best For Head-To-Head Unified Field Theory Model Selection?
I'm seriously considering establishing a prize for unified field theories in-line with my history of prize awards, such as the fusion legislation I drafted with a cofoudner of the AEC's program, the ...
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Does Bohr's solution to Einstein's Light-box experiment work without gravity?
[PS: Not a science student beyond high school]
Hi,
I was reading a book on the debates surrounding interpretations of quantum mechanics (link) and it discussed how the solution to Einstein's Light-box ...
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Physical principles and their rigidity
In many of his talks and interviews, Nima Arkani-Hamed mentions how incredibly constrained are the laws of physics.
For example, in a recent interview he says:
“[I]f we just took these general ...
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Why did the fundamental forces of nature break symmetry in the order they did?
First gravity broke loose, then the strong force and finally there was the separation of the weak and the electromagnetic force? Is this a logical sequence? I guess it has to do with temperature/...
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Uncertainty of the past
If the future today can be described as a complex set of probabilistic wave functions which collapse to form our reality, is it possible that the past history of the universe could also be ...
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The physics community's take on non-commutative geometry
Connes's non-commutative geometry program includes an approach to the Standard Model that employs a non-commutative extension of Riemannian metric. In recent years I've heard physicists say that this ...
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Why do we believe in symmetry being a unifying principle in elementary particle physics?
As far as I can see, symmetry is something that is preferred at lower temperature. For example a crystal lattice has discrete translational symmetries at $T=0$, but at $T>0$ this symmetry is not ...
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Assumed form for beta function
In a classical paper on Hierarchy of Interactions in Unified Gauge Theories, Georgi et al define the renormalization group equation
$$
\mu \frac{\partial g(\mu)}{\partial \mu } =\beta(g(\mu)).
$$
He ...
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Particle fields and field theory
All particles have their own fields. More precisely, I've learned that an electron is just a bundle-up packet of energy from an 'electron field'. So as in this sense, all particles (from the standard ...
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Is there any relation between weak and strong forces, similar to electric and magnetic forces?
Is it possible to unify the strong, weak, electric and magnetic field just by Maxwellian-type equations?
(Maxwell by adding a small change - unified electric and magnetic field, then Einstein's ...
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What did Einstein's unified theory look like, quantitatively?
I'm writing an essay on the history of physics from a mathematical point of view. It's divided into a handful of impactful persons/ideas, one of the largest being the works of Einstein. Immediately ...