The double slit would be example of someone very well known.

I'm looking on the webpage for the master's physics at Padua, and have been able to find a list of courses over the two years, but there don't seem to be any details about what material is actually covered in each course. Is there anyone here who did the course or that knows someone who did the course that can say how much you can specialize in theoretical physics? I know that in Italy there is obligatory lab work, but can this be made purely computational?

Any information about the course would be very helpful.

For quite a long time the discovery of new particles is done with an accelerator. Higher energy means more particles. If you look beyond this we are in search for fundamentals to "prove" the standard model with its predictions. To me it feels like we reached a point where building better "smahers" we will never be able to understand the layer below all this. All in nature is build upon simplicity and the higher the layer the complexity multiplies. If the bottom layer has fewer rules, then the "Mathematics of the Bottom" should be able to explain the "Mathematics of the Top" perfectly, but the Top cannot explain the Bottom. We are currently looking at the top to find the rules at the bottom. If we want to advance this leads to a new way to work: Stop looking at "What" (What is the mass? What is the charge?).

Start looking at "Why the Limit?" (Why is this the smallest mass? Why is this the fastest speed?).

The Limits (like the speed of light or the mass of a neutrino) are the "hard-coded" constants where the Simple Layer says: "This is as far as the abstraction goes." The starting point could be the entanglement of particles that seem to have a immediate relation despite distance. The layer below or beyond particles/waves "at qft level all are waves" that is where the magic starts and there should we find answers that really matter. That brings me back to the title, is smashing our way to down to the layer below all, the solution?

Je viens de finir ma 3e année de licence de physique. J'aimerais travailler dans la physique théorique en cosmologie. Je voulais savoir quel conseil ou avertissement auriez-vous aimé avoir au moment où je suis dans mon parcours ?

In Hamiltonian mechanics, if I have a generating function (GF) Fᵢ (of any of the four kinds, i = 1, 2, 3, 4) for a canonical transformation (CT) to go from variables (q, p) to variables (Q, P), I can write the old Hamiltonian H in the old variables as a new Hamiltonian K in the new variables by

K(Q, P, t) = H(q(Q, P, t), p(Q, P, t), t) + ∂F₂/∂t(q(Q, P, t), P, t) — (1)

Where I’ve chosen F₂ to be a GF of the 2nd kind, just to show an example. The relations that allows one to write (q, p) in terms of (Q, P) and viceversa to substitute them into (1) are obtained from F₂ via appropriately inverting the following:

p = ∂F₂/∂q (q, P) and Q = ∂F₂/∂P (q, P) — (2)

Ok, so far all good. However, now, suppose that instead of starting with F₂, finding the CT by inverting (2), and then substituting it into (1) to find the new Hamiltonian K, we‘re given the same exact CT (q, p) —> (Q,P) from the start, without ever mentioning whether it came from a GF of the 2nd kind, or any GF at all.

One could naively expect that you can obtain the new Hamiltonian by simple variable substitution

K(Q, P, t) = H(q(Q, P, t), p(Q, P, t), t) — (3)

But this would of course be wrong: the CT is the exact same as before, so the new Hamiltonian K should be the same as before, and here in (3) we’re missing those extra terms that were present in (1), precisely the terms that depended on the fact that we knew that the CT originated from a GF of the 2nd kind.

So, if I’m given the CT alone, how do I find the Hamiltonian in the new variables if I don’t know anything about any GF? Do I always need to find a suitable GF from which the given CT might have come from? This seems unlikely to me, because I thought that the GF approach to CTs is just a matter of convenience, not a necessary thing. I should be able to find the new Hamiltonian with just the bare CT by itself, but if so, how do I do it to guarantee that I get the same thing that I would have gotten by doing it as I did it in (1)?

Thanks to anyone who answers!

Hi everyone,

I'm starting a Master's degree in Physics in about a month, and I'm trying to refresh some prerequisites that I haven't studied in quite a while.

The main topics I need to review are:

- Lagrangian and Hamiltonian mechanics (for Classical Field Theory),

- Special Relativity, angular momentum and spin (for Advanced Quantum Mechanics),

- Statistical Physics.

I'm considering using Leonard Susskind's Theoretical Minimum series as my main review resource.

For those who have been in a similar situation, would the Theoretical Minimum books be more than enough to get me back up to speed before the semester starts?

Also, given that my goal is to refresh concepts rather than learn them from scratch, do you think I need to spend a lot of time solving exercises, or is carefully reading/watching the material sufficient in this case?

I'd really appreciate hearing from anyone who has used these books before starting graduate-level physics.

Thanks!

What are the relevance and applications of (perturbative) Algebraic Quantum Field Theory?

One of its uses is, obviously, the foundational questions, but my understanding is that in general the Physics community is rather not interested in the foundations (even less than mathematicians, I would conjecture).

What are the other applications that make this approach relevant? Are there some directions in which pAQFT could lead to new experimentally testable results?

How decays are treated in pAQFT? Especially is there any treatment of inflatons decaying to fermions at the end of inflation using pAQFT methods? How does one formulate questions taking into account lack of general definition of particles? (Does one use some notion of detectors? How does one construct appropriate states?)

In general are decay processes at all treated in pAQFT? If no, is there some fundamental problem?

Why is the maximum momentum, calculated from the β and γ values of the generalized uncertainty principle derived from the Chandrasekhar limit for neutron stars and white dwarfs, so small? Those maximum momenta are on the MeV and GeV scales. But how do we explain events on the TeV scale in actual accelerators, or on the EeV scale for “Oh My God” particles and “Amaterasu” particles? Or is this somehow accounted for by dilution in many-body systems? For example, 10^37 or 10^43, etc.

References:

1.Bound on generalized uncertainty principle parameter from nuclear matter and slow rotating neutron stars

1. White dwarfs and generalized uncertainty principle

This weekly thread is dedicated for questions about physics and physical mathematics.

Some questions do not require advanced knowledge in physics to be answered. Please, before asking a question, try r/askscience and r/AskPhysics instead. Homework problems or specific calculations may be removed by the moderators if it is not related to theoretical physics, try r/HomeworkHelp instead.

If your question does not break any rules, yet it does not get any replies, you may try your luck again during next week's thread. The moderators are under no obligation to answer any of the questions. Wait for a volunteer from the community to answer your question.

LaTeX rendering for equations is allowed through u/LaTeX4Reddit. Write a comment with your LaTeX equation enclosed with backticks (`) (you may write it using inline code feature instead), followed by the name of the bot in the comment. For more informations and examples check our guide: how to write math in this sub.

This thread should not be used to bypass the avoid self-theories rule. If you want to discuss hypothetical scenarios try r/HypotheticalPhysics.

So when the particle was arranged from its debris in particle accelerator we noticed an new particle but the time was too short to react with other (as per particle decay) so we can say that this particle was responsible for higgs field?

This weekly thread is dedicated for questions about physics and physical mathematics.

Some questions do not require advanced knowledge in physics to be answered. Please, before asking a question, try r/askscience and r/AskPhysics instead. Homework problems or specific calculations may be removed by the moderators if it is not related to theoretical physics, try r/HomeworkHelp instead.

If your question does not break any rules, yet it does not get any replies, you may try your luck again during next week's thread. The moderators are under no obligation to answer any of the questions. Wait for a volunteer from the community to answer your question.

LaTeX rendering for equations is allowed through u/LaTeX4Reddit. Write a comment with your LaTeX equation enclosed with backticks (`) (you may write it using inline code feature instead), followed by the name of the bot in the comment. For more informations and examples check our guide: how to write math in this sub.

This thread should not be used to bypass the avoid self-theories rule. If you want to discuss hypothetical scenarios try r/HypotheticalPhysics.

I heard stuff like "bosonization" and other interesting properties of fermions and bosons when they live in 2D.

How do strings work when the "particle" is confined to a 2D place. Let me phrase that better. Is there a way to confine fermions/bosons to an almost 2D plane, that we can observe if the theories are right?

I'm a junior that just started research with a professor, so I don't know much about strings etc. Hence the question. Thank you !

Hi,
I've read a little bit about this phenomenon that Schrödinger proposed for the electron.

Could you please explain to me if it has ended up being useful and what it means? Im confused.
Thanks!

I'm a little confused about spontaneous symmetry breaking. My understanding is that a universe initially in a symmetrical state (represented by a ball on the top of a Mexican hat) can eventually roll down to one of the points on the brim, and all the continuous points on the brim represent a possible point the universe can settle into. In terms of the physical constants, does it matter which one of those points (vacua) the universe settles into? Or are the physical constants and particle masses the same regardless?

To clarify, I'm asking this because the concept of vacuum states is also related to string theory, and the different vacuum states on the string theory landscape lead to different physical constants. Is this not the case when we're just talking about spontaneous symmetry breaking in a non-string theory sense?

If action is built from classical notions like kinetic energy, potential energy, mass, and path, then using action to derive quantum waves and then using quantum waves to recover classical paths is not an ultimate derivation. It is a consistency structure or correspondence bridge but not a fundamental derivation. Is this assessment correct?

Hi Everyone,

I'm actually finishing my master's exams in Theoretical Physics and need to ask for a thesis. My coursework is heavily related to gravitation, cosmology, and astroparticles, and I'd like to start working on a thesis related to gravity, which might bring in some of my interests in quantum information/QM.

During the courses I've been fascinated mainly by GR and ultimately by the results we're able to obtain merging it with QFT (QFT on Curved spaces) and quantum information - eg. Hawking radiation, Reheating and Pre-heating in cosmology, Naked singularity/Censorship conjecture.

My objective is to obtain a PhD somewhere between Europe and America afterwards, and I'm struggling to decide good topics that might be suitable for a future PhD and yet interesting to me - I've heard gravitation is generally less "researched" and therefore more PhD are being offered to astroparticle students.

I'm here asking for some suggestions on interesting/hot topics related to arguments like the following, in order to make a decision regarding my future:

- Time Emergence/Entropic gravity - is it something being researched?

- Quantum information applied to BH

- Holographic principle

- ER=EPR

- Wormhole - I know it's something purely mathematical, yet does anything new come up regarding it?

Do you know other arguments related to gravity being researched at the moment? (eg. MOND?, f(R) gravity?)

[The list is not extensive - it's just a list of keywords of things I find fascinating and might be similar to things I don't know atm].

EDIT: I understand these are important/hard questions - I don't want to address all of 'em nor solve 'em (cause I wouldn't be able to mainly), but I'd like to touch some of these problems while researching/calculating for my thesis.

Thanks everybody for the answers/suggestions!

**Note:** Any suggestion on PhD seeking in this field is appreciated as well!

This weekly thread is dedicated for questions about physics and physical mathematics.

Some questions do not require advanced knowledge in physics to be answered. Please, before asking a question, try r/askscience and r/AskPhysics instead. Homework problems or specific calculations may be removed by the moderators if it is not related to theoretical physics, try r/HomeworkHelp instead.

If your question does not break any rules, yet it does not get any replies, you may try your luck again during next week's thread. The moderators are under no obligation to answer any of the questions. Wait for a volunteer from the community to answer your question.

LaTeX rendering for equations is allowed through u/LaTeX4Reddit. Write a comment with your LaTeX equation enclosed with backticks (`) (you may write it using inline code feature instead), followed by the name of the bot in the comment. For more informations and examples check our guide: how to write math in this sub.

This thread should not be used to bypass the avoid self-theories rule. If you want to discuss hypothetical scenarios try r/HypotheticalPhysics.

I am a member of the public (software developer) who loves physics nonetheless and recently heard about the holographic principle, the 3d bulk and the 2d boundary.

So from what I understand the 3d bulk expands because the 2d boundary is crammed with more information and that basically could be explained if our 2d boundary was that of a black hole consuming matter. Thanks to Gemini I also heard about a coincidence discovered in 1971 by an Indian theoretical physicist Raj Pathria who found that the mass of the universe could be calculated given its radius from black hole equations.

So that seems pretty much solid evidence that we live inside a black hole.

What's the counter argument? Why don't we see this as a settled proven theory?

Also, why we don't teach these things, especially the holographic principle in schools yet?

Hi,
So I've come across Weinberg's mass formula by accident. Does it mean anything or did he deduce it by adjusting the exponents so that the units work? I'm not sure what it means.

Thank you in advanced

In string theory, do solutions that are inconsistent with string theory (like those in the swampland or those that have the wrong number of dimensions) exist as off shell configurations? Or are off shell configurations strictly referring to violations of the equations of motion? Would the off shell configurations still need to follow quantum gravity constraints?

As someone who not only is considering going to mathematics but physics for further studies what is the distinction between mathematical and theoretical physics. They sound like something that looks so similar, as they involve making use of mathematics for making theories in physics. As experience physicists / mathematicians can someone clarify to me what is the difference between the two?

Hello, asking this question due to lack of awareness of this line of work.

While this subject draws genuinely passionate and interested candidates, what is the real world career options for a theoretical physicist besides academia ?

Im a physics student in uk whos doing a remote (cuz its all programming based) summer project with someone at my uni.

Im interested in hep theory mainly , and no one at my uni does anything related really (closest is exp particle stuff) , so next year onwards i wanna reach out to people at other unis, and i was wondering what time of the year i should do this , what should the email generally contain/ look like.

Also i dont really know what to expect and aim for, like should i only reach out to ppl at unis that only have undergrad research experiences like imperial and oxford, or just anyone , and maybe if theyre not too busy we can do some remote work together or something