HEP-Th vs. HEP-Lat for PhD

[raoadithya]

Hi,

I am a master's student from India (with a CGPA of 9.75/10.0, equivalent to 3.9/4.0) who will be graduating in July, and so I am looking for PhD positions (in Europe).
I am torn between selecting hep-th and selecting hep-lat for my PhD research. I have hands on research experience in both Theoretical Quantum Yang-Mills and Lattice Gauge Simulations , and I find both of them interesting and fun to work with.

My primary concern is that if I pursue hep-lat, then I will miss out on the three years of training in theory methods, which might mean that later on, in case I decide to switch fields, I won't be able to get a postdoc or other positions in theory. On the other hand, if I go for hep-th, and at the same time keep my programming skills updated, it should be possible to switch fields later.
Another concern is job prospects, hep-lat will give me easily transferable skills in programming, while hep-th will give me lesser transferable skills (as far as I see it).
A point worth mentioning is that my master's degree is in physics and not theoretical physics, meaning I haven't taken any special lectures in string theory, general relativity, etc., which I think might hinder my chances of getting a position in theory in Europe.

Please share some perspectives regarding the same, helping me make a decision.

 

[Vanadium 50]

(1) Didn't you miss the application deadlines? People are getting offers now.
(2) Nobody can predict which opportunities will be available to you in the future - with either path.
(3) A PhD in lattice is not the same as being a code monkey.

 

[ohwilleke]

Hep-Lattice has the virtue of not being overcrowded because it is less "glamorous". It is also a field in which there will be plenty of scientifically valuable work to do for the foreseeable future calculating predicted outcome for collider physics experiments, and hadron properties. Finding promising research to do is trivially easy. You won't flounder for years trying to come up with a dissertation topic. The lower level of competition means you can be quite successful being very smart, but not an Einstein/Feymann class genius.

In the longer term, hep-lat is also increasingly segueing into work in quantum gravity and numerical general relativity, some of which use lattice methods usually reserved for QCD to address GR and quantum gravity questions.

Hep-lat people also tend to have more interactions with experimentalists and phenomenologists than hep-theory people do, which can keep you more connected to the employment rumor mill. There are also probably more post-doc positions in hep-lat because hep-experimentalists need hep-lat people to work hand in hand with them in greater numbers than they need hep-theory people.

Hep-Theory is a more overcrowded sub-discipline of high energy physics. But it is harder to find promising research opportunities, especially these days, as we are in something of a desert of experimental hints of new physics to drive hep-theory. You can spend years floundering around looking for a worthy dissertation topic that can meaningfully add to the existing work in the field, especially if you don't already have one in mind now.

Those observation/experimental data anomalies that do pop up or are suggested by theoretical considerations are mostly already mobbed with large numbers of researchers writing papers on almost every angle building on an already large existing literature. If you find your niche it is easy to get citations from your sub-sub-field, but even you you make an advancement in theoretical physics, you'll have to share credit with the dozen other theoretical physicists who have also worked on the same problem and got the key insight which you refined later.

Both hep-lat and hep-theory are cheap in terms of the institutional cost of supporting professors and graduate student assistants. Hep-lat is a bit more expensive because it requires expensive computers, while hep-theory requires little more than a laptop, a white board, a tiny office, and some stationary. Still, they are both easier for smaller budget institutions (both universities and colleges on one hand, and free standing research institutes like the Perimeter Institute on the other), to support positions in, while hep-ex is super expensive, limiting the number of institutions that can afford to establish positions in that field.

Neither are ideal for transitioning to a non-physics job. I think that your intuition that hep-lat has somewhat more transferrable skill sets than hep-theory is probably right. And, your are likely to have a steadier stream of publishable work product in hep-lat than in hep-theory. But in a transition to a non-physics job, your undergraduate math and IT skills are more relevant than anything you learn in graduate school in either field.

The dream non-physics job for former physicists, is quantitative securities and commodities trading jobs with large institutional investors in the finance industry, but those jobs are wickedly hard to obtain and require at least some mid-level economics and finance background.

Either subfield is suitable for college teaching of physics, once you get your PhD, since a lot of that, especially for junior faculty, involves teaching introductory and intermediate level undergraduate courses that aren't specific to either subfield anyway. Until you are a senior full professor, you'll be lucky to teach more than one or two advanced classes related to your subfield at year.

 

[Vanadium 50]

Hep-Lattice has the virtue of not being overcrowded

Reference, please?

I define crowding as number of people seeking slots divided by the number of slots. Just the number of slots is not "crowded". It is "small".

 

[raoadithya]

In the longer term, hep-lat is also increasingly segueing into work in quantum gravity and numerical general relativity, some of which use lattice methods usually reserved for QCD to address GR and quantum gravity questions.

Could you please provide references for HEP-Lat addressing questions in Quantum Gravity?

Also, could you give me a rough perspective on how my situation would be if I were to go for a PhD in HEP-Lat and then for postdoc, I decide to switch to HEP-Th?

Thank you very much for taking your time to answer my question. It was pretty informative and gave me the answers I was looking for.

 

[renormalize]

Could you please provide references for HEP-Lat addressing questions in Quantum Gravity?

A recent reference is https://arxiv.org/abs/2209.06555.