What classes should I take to go into String Theory?

[QuantumCurt]

Hey everyone, I've been trying to get a rough idea of what types of classes I should be taking for my upper level undergrad courses, and get an early idea of what type of graduate elective courses I should be taking. I'm a double major in physics and math, and plan to go to grad school for physics.

I'm still somewhat undecided on what exactly I want to go into. I'm very deeply interested in cosmology, but lately particle physics and string theory have really been catching my attention. What types of courses would be appropriate as a primer to go into research for string theory? I'm assuming particle physics courses would be my best bet. Yes?

What types of fields would be open to me with those interests? Is there any field that meets at the crossroads of string theory/particle physics and cosmology?

Are there any other specific classes that I should be taking to prep for study in these fields, or should I just worry about the standard curriculum?

 

[Aimless]

I'm still somewhat undecided on what exactly I want to go into. I'm very deeply interested in cosmology, but lately particle physics and string theory have really been catching my attention. What types of courses would be appropriate as a primer to go into research for string theory? I'm assuming particle physics courses would be my best bet. Yes?

At the undergrad level, take whatever courses you can find that interest you. The purpose of these electives is not to prepare you for doing research in that area as a grad. student, it is merely to give you a taste of these areas of research so that you might be able to better decide where you want to focus as a grad. student. String theory in particular is extremely mathematically intensive, and it is unlikely that any course taught at an undergraduate level could truly prepare you for research in the field; that type of preparation will come once you are a grad. student and have chosen your focus.

That said, I caution you to stay away from cosmology; the market is saturated and there is no funding, so you will not find jobs in cosmology after you graduate. String Theory is slightly better, having seen some resurgence lately due to the AdS/CFT correspondence (which is more closely related to particle physics than it is cosmology), although I don't know if that will still be the case by the time you're finished with your PhD. In generally, you will be better off picking a research area where there are immediate practical applications (and, hence, funding).

 

[Sentin3l]

That said, I caution you to stay away from cosmology; the market is saturated and there is no funding, so you will not find jobs in cosmology after you graduate. String Theory is slightly better, having seen some resurgence lately due to the AdS/CFT correspondence (which is more closely related to particle physics than it is cosmology), although I don't know if that will still be the case by the time you're finished with your PhD. In generally, you will be better off picking a research area where there are immediate practical applications (and, hence, funding).

This is slightly off-topic; but which area of high energy theory is the most open right now? I am primarily interested in nonequilibrium QFT and theories of quantum gravity with a secondary interest in inflation. So I was wondering how those markets are currently.

 

[cytochrome]

There's no limit to how much math you can take. I would take some pure math courses that are heavily loaded with proofs, since much of string theory research is heavily intertwined with mathematics research and publications basically revolve around proofs

 

[Aimless]

This is slightly off-topic; but which area of high energy theory is the most open right now? I am primarily interested in nonequilibrium QFT and theories of quantum gravity with a secondary interest in inflation. So I was wondering how those markets are currently.

Hmmm. Most open? None of them are all that open, but probably the most popular quantum gravity theory these days is LQG. CDT seems to be picking up some interest, too, although I haven't seen much in the way of jobs in that area. As a said above, there are still quite a few String Theory positions available, thanks to the AdS/CFT correspondence, but String Theory has shifted away from quantum gravity back towards particle physics as a result.

I should note that I'm not the most qualified one to answer this; my research is in semiclassical gravity, so I'm only tangentially related to the quantum gravity folks. My assessments are based primarily on how many postdoc job openings I see for various groups/fields.

 

[Sentin3l]

Hmmm. Most open? None of them are all that open, but probably the most popular quantum gravity theory these days is LQG. CDT seems to be picking up some interest, too, although I haven't seen much in the way of jobs in that area. As a said above, there are still quite a few String Theory positions available, thanks to the AdS/CFT correspondence, but String Theory has shifted away from quantum gravity back towards particle physics as a result.

I should note that I'm not the most qualified one to answer this; my research is in semiclassical gravity, so I'm only tangentially related to the quantum gravity folks. My assessments are based primarily on how many postdoc job openings I see for various groups/fields.

Regardless, you probably have a better view of the research arena than I do, so thanks for your perspective.

 

[QuantumCurt]

At the undergrad level, take whatever courses you can find that interest you. The purpose of these electives is not to prepare you for doing research in that area as a grad. student, it is merely to give you a taste of these areas of research so that you might be able to better decide where you want to focus as a grad. student. String theory in particular is extremely mathematically intensive, and it is unlikely that any course taught at an undergraduate level could truly prepare you for research in the field; that type of preparation will come once you are a grad. student and have chosen your focus.

That said, I caution you to stay away from cosmology; the market is saturated and there is no funding, so you will not find jobs in cosmology after you graduate. String Theory is slightly better, having seen some resurgence lately due to the AdS/CFT correspondence (which is more closely related to particle physics than it is cosmology), although I don't know if that will still be the case by the time you're finished with your PhD. In generally, you will be better off picking a research area where there are immediate practical applications (and, hence, funding).

I keep hearing similar things elsewhere regarding cosmology. The fact that I keep hearing this all over the place is really making me lean away from it. When I first became interested in physics, astrophysics/cosmology was where my main interests lie. As I've done more research in the different fields that are available though, I really keep leaning towards particle physics/string theory. I definitely want to pick a field that I'll be able to do find work in relatively easily.

I've been planning on taking an astrophysics concentration within my physics major, but I'm starting to rethink that. It would consist of roughly 20 hours of coursework, but I'm starting to think that I would be better off using those undergrad elective credits for other courses such as a second QM sequence, a particle physics sequence, or some field theory. Would it be unusual for an undergrad to take these courses?

There's no limit to how much math you can take. I would take some pure math courses that are heavily loaded with proofs, since much of string theory research is heavily intertwined with mathematics research and publications basically revolve around proofs

What type of math would you suggest? I'm planning on double majoring in physics and math, so I'll be taking real analysis, abstract algebra, complex analysis, differential geometry, geometric analysis, advanced differential equations...plus some elective courses. From what I've gathered, courses such as vector and tensor analysis, partial differential equations, and topology are going to be very important. What other types of math courses should I consider?

 

[WannabeNewton]

It is far from unusual for an undergrad to take graduate QM classes and, to a much lesser extent, field theory classes (by which I mean QFT since classical field theory is not as difficult at the introductory level) at some point in undergrad e.g. senior year. If you are advanced enough with regards to your undergraduate classes then you can attempt such classes if your department allows it; I personally know peers who have done so. With regards to the math, I would just add functional analysis. Try to take an undergraduate general relativity class if your school offers one.

 

[atyy]

I definitely want to pick a field that I'll be able to do find work in relatively easily.

I've heard that there is no such field in physics, especially physics that is done only in academia, like string theory.

It is far from unusual for an undergrad to take graduate QM classes and, to a much lesser extent, field theory classes (by which I mean QFT since classical field theory is not as difficult at the introductory level) at some point in undergrad e.g. senior year. If you are advanced enough with regards to your undergraduate classes then you can attempt such classes if your department allows it; I personally know peers who have done so. With regards to the math, I would just add functional analysis. Try to take an undergraduate general relativity class if your school offers one.

All my classmates from undergrad who went on to string theory had done QFT, and even the string theory class (at that time there was only a graduate string theory class, unlike nowadays).

 

[QuantumCurt]

It is far from unusual for an undergrad to take graduate QM classes and, to a much lesser extent, field theory classes (by which I mean QFT since classical field theory is not as difficult at the introductory level) at some point in undergrad e.g. senior year. If you are advanced enough with regards to your undergraduate classes then you can attempt such classes if your department allows it; I personally know peers who have done so. With regards to the math, I would just add functional analysis. Try to take an undergraduate general relativity class if your school offers one.

Forgot to mention that...general relativity is another course I would try to take. I'm in a community college right now, but I'm planning on transferring to UIUC. They offer a two course sequence in general relativity, but they're 500 level, so technically graduate level classes.

It looks like UIUC does have a functional analysis class, so I'll add that to the potential list. It looks like they have the grad level real analysis class as a prerequisite though.

I think it's going to be damn near impossible to finish my bachelors within two years after transferring...lol...But, I'm not opposed to spending and extra year as an undergrad if I have to. I'd rather have the coursework done, so I can use my electives in grad school for really advanced classes.

Thanks for the help!

 

[WannabeNewton]

Just focus on your required physics classes e.g. intermediate mechanics, EM, and stat mech before jumping into really advanced stuff.

 

[QuantumCurt]

I've heard that there is no such field in physics, especially physics that is done only in academia, like string theory.

Yeah, I've heard the same thing. But...I'd like to go into a field that will be easier than other fields to find work in. From what I've gathered, string theory is one of the bigger fields in theoretical physics right now, and I find it incredibly fascinating. So, it seems like a good path at this point.

 

[QuantumCurt]

Just focus on your required physics classes e.g. intermediate mechanics, EM, and stat mech before jumping into really advanced stuff.

Yeah, definitely. I've still got a long way to go before I really have to start picking out advanced classes. But, I'm the type of person that likes to think really far ahead as far as my classes go. I don't plan out any other aspect of my life though, I'm a pretty "spur of the moment" kind of person in every aspect of my life outside of academia.

 

[atyy]

Yeah, I've heard the same thing. But...I'd like to go into a field that will be easier than other fields to find work in. From what I've gathered, string theory is one of the bigger fields in theoretical physics right now, and I find it incredibly fascinating. So, it seems like a good path at this point.

Well, I'm a biologist, so not really qualified. But I've often heard that since a job is not guaranteed, one may as well do what one loves if funding and circumstances permit. That's the advice too in biology, so maybe it's plausible for physics. So it's good that you are pursuing string theory because of your interest. (One crazy string theorist has recently suggested it's related to what neurobiologists like me think about , not sure whether it's right, but lol.)

 

[QuantumCurt]

Well, I'm a biologist, so not really qualified. But I've often heard that since a job is not guaranteed, one may as well do what one loves if funding and circumstances permit. That's the advice too in biology, so maybe it's plausible for physics. So it's good that you are pursuing string theory because of your interest. (One crazy string theorist has recently suggested it's related to what neurobiologists like me think about , not sure whether it's right, but lol.)

I just read that abstract, that sounds like an interesting paper. I'm going to have to give it a look.

My interests are really what's driving me towards string theory. My interests initially made me lean toward astrophysics/cosmology, but as I've researched my options more...my interests have really changed. I still have a long way to go in physics academically, but from an outside perspective, my interests keep leading me towards particle physics and string theory. The "lucrative" nature of a given field is obviously a consideration, but it's not going to be the ultimate deciding factor for me. I'd rather follow my passions, even if it isn't going to be the most lucrative option.

 

[cytochrome]

What type of math would you suggest? I'm planning on double majoring in physics and math, so I'll be taking real analysis, abstract algebra, complex analysis, differential geometry, geometric analysis, advanced differential equations...plus some elective courses. From what I've gathered, courses such as vector and tensor analysis, partial differential equations, and topology are going to be very important. What other types of math courses should I consider?

I think you pretty much nailed it. If you can take all of those then that would be great. Differential geometry, PDE, and topology are extremely important for string theory. Vector analysis and ODE will come in your lower level pre-requisites

 

[WannabeNewton]

From what I've gathered, string theory is one of the bigger fields in theoretical physics right now, and I find it incredibly fascinating. So, it seems like a good path at this point.

https://www.physicsforums.com/blog.php?b=3727
Read this.

 

[cgk]

I really wonder why everyone always wants to do string theory or cosmology and the like, instead of theoretical subjects which might actually shed some insights about the world we live in... (e.g., condensed matter, electronic structure, statistical mechanics, geophysics...)

 

[DimReg]

For graduate courses, I would say the bare minimum is General Relativity and quantum field theory. Those are the two subjects that String theory is supposed to "replace", so you should know them well. In addition, a healthy dose of advanced math is important: complex analysis, differential geometry and topology are essential.

 

[ZombieFeynman]

Yeah, I've heard the same thing. But...I'd like to go into a field that will be easier than other fields to find work in. From what I've gathered, string theory is one of the bigger fields in theoretical physics right now, and I find it incredibly fascinating. So, it seems like a good path at this point.

This is not true at all. At my institution we have 4 grad students and 2 professors working on string theory. In theoretical condensed matter we have over 20 grad students, 8 postdocs and 7 professors. I think this is largely the case across the country, except perhaps at a couple schools.

 

[Nabeshin]

This is not true at all. At my institution we have 4 grad students and 2 professors working on string theory. In theoretical condensed matter we have over 20 grad students, 8 postdocs and 7 professors. I think this is largely the case across the country, except perhaps at a couple schools.

The point was that everyone on these forums always has the dream of doing theoretical physics, which in their minds is equivalent with string theory & quantum gravity.

You can thank people like Brian Greene and Stephen Hawking for that, since I don't know of any prominent popularizers of condensed matter research (or experiment in general, for that matter).

 

[WannabeNewton]

Admittedly, it is probably harder to popularize theoretical condensed matter. It is extremely technical in every which way you look and draws on many complicated physical theories (stat physics, QFT, EM etc.) whereas something like general relativity is very easy to popularize without ever going into the technical details if you just throw in a bunch of romantic terms and use some cool computer animations and get Morgan Freeman to talk about time travel.

 

[QuantumCurt]

https://www.physicsforums.com/blog.php?b=3727
Read this.

That was a good read, thanks for the link.

For graduate courses, I would say the bare minimum is General Relativity and quantum field theory. Those are the two subjects that String theory is supposed to "replace", so you should know them well. In addition, a healthy dose of advanced math is important: complex analysis, differential geometry and topology are essential.

Thanks for the input. From what I've been gathering, those are going to be some of the most crucial classes. I'm definitely going to do whatever I can to get them done in undergrad.

This is not true at all. At my institution we have 4 grad students and 2 professors working on string theory. In theoretical condensed matter we have over 20 grad students, 8 postdocs and 7 professors. I think this is largely the case across the country, except perhaps at a couple schools.

You would probably know better than I would. I don't really know what path I'll end up going down, but from where I sit so far, particle physics is what has really grabbed my attention. It may not be as lucrative as other fields, but in the end that's not the ultimate concern.

The point was that everyone on these forums always has the dream of doing theoretical physics, which in their minds is equivalent with string theory & quantum gravity.

You can thank people like Brian Greene and Stephen Hawking for that, since I don't know of any prominent popularizers of condensed matter research (or experiment in general, for that matter).

I'm sure the popularizers of physics do put out a very inaccurate view of what the field really consists of. I realize that there is a lot more to theoretical physics than just string theory and quantum gravity...but so far, that's where the arrow keeps pointing me. There are plenty of branches on that road though, and I'm sure my mind will change another hundred or so times before I finally pick a final path.



Thanks for the input everyone. :)

 

[ahsanxr]

Right now I'm interested in and looking to go into string theory and the related mathematics. I'll be starting my 4th year in the fall and here are the classes I recommend you take:

Physics: Classical mechanics, Stat Mech, E&M, 2 semesters QM are the fundamentals. Then you should take graduate QM (at least the first semester, second one not so essential), QFT, and GR. A graduate "math methods for physics" course could also be useful since certain math topics such as green's functions are not usually taught in a traditional math course. (I'll have all of these by graduation).

Math: Abstract algebra, group representations & lie groups/algebras, real and complex analysis, PDEs, topology, differential geometry. algebraic topology and functional analysis could also be useful. (still deciding on functional but other than that I'll have all of these too.)

 

[WannabeNewton]

Where's the love for condensed matter theory ? Someone start a "What classes should I take to go into theoretical condensed matter theory" thread!

 

[atyy]

Where's the love for condensed matter theory ? Someone start a "What classes should I take to go into theoretical condensed matter theory" thread!

String theory is condensed matter

It's Brian Swingle's "intermediate value theorem" http://pirsa.org/13050027/ see 2:30 - 4:40;)

 

[QuantumCurt]

Right now I'm interested in and looking to go into string theory and the related mathematics. I'll be starting my 4th year in the fall and here are the classes I recommend you take:

Physics: Classical mechanics, Stat Mech, E&M, 2 semesters QM are the fundamentals. Then you should take graduate QM (at least the first semester, second one not so essential), QFT, and GR. A graduate "math methods for physics" course could also be useful since certain math topics such as green's functions are not usually taught in a traditional math course. (I'll have all of these by graduation).

Math: Abstract algebra, group representations & lie groups/algebras, real and complex analysis, PDEs, topology, differential geometry. algebraic topology and functional analysis could also be useful. (still deciding on functional but other than that I'll have all of these too.)

I've looked at some of the different math methods in physics type courses too. That's an option I'm definitely going to keep in mind if I don't have time to squeeze in all of the upper level math that I'd like.

Where's the love for condensed matter theory ? Someone start a "What classes should I take to go into theoretical condensed matter theory" thread!

Condensed matter is just too heavy for me...I don't know if I could handle that much mass. Strings are much more manageable...lol

String theory is condensed matter

It's Brian Swingle's "intermediate value theorem" http://pirsa.org/13050027/ see 2:30 - 4:40;)

Yeah!