## Tuesday, December 6, 2016

### Podcast 1

Hey y'all! Check out Taylor and me in our first combined podcast, aptly titled Podcast 1! In it, I interview Taylor about life after undergrad, grad school, life, and the universe.

Enjoy,

SMK

## Friday, October 28, 2016

### Podcast 0

Here is 7 minutes of me explaining the basics behind what I did over the past summer. It isn't the most articulate or the most well produced podcast, but it is a podcast. Hopefully interesting to anyone looking for a cursory glance at QFT on the lattice.

Enjoy,

TEJ

## Wednesday, September 7, 2016

### Year Two: New Apartment, New Courses, more Lattice and now Gamma Ray Bursts

Time for a second blog post. I will readily admit we have been a bit slow with the blog. There have been a lot of new developments in the interim. Things that Have prevented us from doing too much here, but we are trying to change that. We have a basecamp now, and we are actually divvying up tasks and setting due dates. There will be some hits and misses as we try and get our new podcast off the ground -- likely some ugly moments -- but that all needs to happen. That will be posted here as soon as it is ready and I will share some more personal updates in the meantime.

I am now in my second year of a physics PhD program. As a second year graduate student, I am starting to feel like I actually am a research physicist. Before tackling my physics life, I'll tell you some happenings in my life. My S.O.and I moved apartments and were able to rent without a guarantor--something that felt like a major adult milestone. I have been biking to work of late. According to the vlogbrothers, that puts me among the happiest of commuters: One Scientifically Proven Thing Actually Makes People Happier. I do not know if I would agree during the ride, but there is a certain satisfaction in arriving.

I spent the summer working with scalar Quantum Field Theories on the lattice. Specifically, I have been examining Phi4 theory. For those of you interested, I refer you to Peskin and Schroeder, as well as Rothe: Lattice Gauge Theories. For those of you looking only for a flavor, let me explain a bit further. A scalar field theory can be best described as the field theory describing a gas of bosons. Instead of treating these bosons as particles, we treat them as disturbances within a field that spans all the spatial dimensions as well as time. The dynamics of the field are contained within the Feynman Path Integral formalism.

The path integral can be thought of as an integral over all possible field configurations with each path weighted by a complex exponential of the action. The complex exponential makes calculating the results of the path integral difficult because it is hard to determine which paths contribute to the integral and which paths are suppressed (a complex exponential can be expanded into cos(x)+i*sin(x) where i is the \sqrt{-1}).

In lattice field theory, we get around this by converting our time variable into something called imaginary time or t-> i*t, this conversion removes the complex portion of the exponential (It also moves us out of our standard Minkowski space, which is the metric space that Relativity needs to function, but that is neither here nor there at the moment...). This new path integral is called the Euclidean path integral and the action the Euclidean action. With the decaying exponential, we can now use analytic methods to calculate the observables of a free particle, but the integral cannot be solved analytically in most cases.

For those, we use what is a Metropolis Monte Carlo algorithm. I am currently working on a write-up that describes this in detail. Until that time, know that the general idea is that we select paths with a probability based on the distribution defined by the decaying exponential in the path integral. There are additional complications when dealing with fermions, but the scalar field case is useful because it allows us to explore new methods for implementing the Monte Carlo on something that is not computationally intractable, and can be solved through other means.

This post has already been rambling for quite some time, so I will cut the QFT discussion of there. I did explore additional aspects of simulating the path integral, but those are still active areas of my research, and needs to be explored further. I will quickly mention my other project, which is modeling Gamma Ray Bursts by scaling shockwave models to determine physical parameters of the shockwave based on key frequencies and fluxes in their spectrum, but I have only been on this project about a week.

Look for more updates on all of these topics, as well as our first podcast, by mid-October.

Cheers,

TEJ

I am now in my second year of a physics PhD program. As a second year graduate student, I am starting to feel like I actually am a research physicist. Before tackling my physics life, I'll tell you some happenings in my life. My S.O.and I moved apartments and were able to rent without a guarantor--something that felt like a major adult milestone. I have been biking to work of late. According to the vlogbrothers, that puts me among the happiest of commuters: One Scientifically Proven Thing Actually Makes People Happier. I do not know if I would agree during the ride, but there is a certain satisfaction in arriving.

I spent the summer working with scalar Quantum Field Theories on the lattice. Specifically, I have been examining Phi4 theory. For those of you interested, I refer you to Peskin and Schroeder, as well as Rothe: Lattice Gauge Theories. For those of you looking only for a flavor, let me explain a bit further. A scalar field theory can be best described as the field theory describing a gas of bosons. Instead of treating these bosons as particles, we treat them as disturbances within a field that spans all the spatial dimensions as well as time. The dynamics of the field are contained within the Feynman Path Integral formalism.

The path integral can be thought of as an integral over all possible field configurations with each path weighted by a complex exponential of the action. The complex exponential makes calculating the results of the path integral difficult because it is hard to determine which paths contribute to the integral and which paths are suppressed (a complex exponential can be expanded into cos(x)+i*sin(x) where i is the \sqrt{-1}).

In lattice field theory, we get around this by converting our time variable into something called imaginary time or t-> i*t, this conversion removes the complex portion of the exponential (It also moves us out of our standard Minkowski space, which is the metric space that Relativity needs to function, but that is neither here nor there at the moment...). This new path integral is called the Euclidean path integral and the action the Euclidean action. With the decaying exponential, we can now use analytic methods to calculate the observables of a free particle, but the integral cannot be solved analytically in most cases.

For those, we use what is a Metropolis Monte Carlo algorithm. I am currently working on a write-up that describes this in detail. Until that time, know that the general idea is that we select paths with a probability based on the distribution defined by the decaying exponential in the path integral. There are additional complications when dealing with fermions, but the scalar field case is useful because it allows us to explore new methods for implementing the Monte Carlo on something that is not computationally intractable, and can be solved through other means.

This post has already been rambling for quite some time, so I will cut the QFT discussion of there. I did explore additional aspects of simulating the path integral, but those are still active areas of my research, and needs to be explored further. I will quickly mention my other project, which is modeling Gamma Ray Bursts by scaling shockwave models to determine physical parameters of the shockwave based on key frequencies and fluxes in their spectrum, but I have only been on this project about a week.

Look for more updates on all of these topics, as well as our first podcast, by mid-October.

Cheers,

TEJ

## Wednesday, May 18, 2016

### Our New Podcast and My First Year of Graduate School

I am currently a Physics PhD student going to school in Washington, DC. I just finished my first year of courses and teaching earlier in the week, and now I am excited to have some time to work on this project. This blog is hopefully going to be the basis for a podcast produced by a good friend of mine from Undergrad and myself. It is still being built, so pardon the appearance. We are both physicists by degree (although he has since transitioned to the dark arts of Electrical Engineering in the evil land of Industry) and we want to share our love of science and technology with the world.

The name is a bit of nostalgia from our time studying. The physics student lounge was where we spent most of our undergraduate lives not only doing work, but also coming to outrageous conclusions about life and being entirely hyperbolic. With any luck our podcast will capture all of that wonderful knowledge and absurdity, and provide--at the very least--some manner of amusement to the listener.

In the mean time, I am going to attempt to provide some content and share a bit of my experience as a (now) second year graduate student. The first year was quite an adventure. I went from being an undergraduate with a full course load of: physics, math, and liberal arts courses to dealing exclusively in physics full-time, alongside teaching laboratory sections. It was a big transition and there were a lot of times when I was not sure if I could make it. But here I am, sat at my computer with some tea on a rainy day, and feeling like reminiscing.

**I have learned a lot:**

- Group Theory is actually deeply embedded in so much of physics. Every course I took in the past year dealt with groups. (I am really excited about Group Theory, but I will save that for another post)
- Graduate Courses move very quickly. The course is not necessarily about learning deeply, it is about exposing you to everything. The deep learning is your responsibility.
- Credit Hours are not representative of work required. The course requires what it requires to learn the material. Credit Hours are simply a bureaucratic thing.
- Attitudes about learning and students are very different at large universities. Students and Professors seem to view the interaction and the course itself much more like a business transaction. Something that took a lot of getting used to coming from a liberal arts college.
- Teaching on your own is terrifyingly rewarding. My first semester, I had 4 labs that I was in charge of organizing, teaching, and evaluating. My lead instructor essentially gave me a few guidelines on what he expected from the labs, but left the quizzes and actual grading structure to me. Initially, this was terrifying, but I am really appreciative of this experience in hindsight. Having dealt with that out of the gate has made me a much more confident instructor.
- C, LaTeX and Mathematica/Octave/Gnuplot are everywhere. There is no escaping them. Linux is also an eventuality if you are pursuing an advanced degree in physics. You cannot fight it forever.
- Black Coffee is a miracle. I have nothing more to say.
- Always sleep when you can. Your schedule is going to be erratic for the next while.
- Make time for friends and family. You need contact with the outside world to stay sane.
- Don't lose sight of what you are interested in. It is so easy to become entirely engrossed in the coursework and teaching and entirely forget what it is you came here for. That can be incredibly demoralizing and hurt your overall graduate school experience in the first year. Keep up with new research in the field, listen to podcasts, attend lectures, do whatever it takes to stay connected with what you love about the field and motivated in what you are doing.

I have other thoughts on the nature and culture of Graduate programs, but I will save those for another post. Right now, I am content to have survived my first year, and am excited to move forward into my summer work. For the intrepid reader I am hoping to share my experiences working with Gauge Theories on the Lattice this summer.

Cheers,

Cheers,

TEJ

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