2,411 reputation
11332
bio website berkeley.academia.edu/…
location Berkeley, CA
age 25
visits member for 3 years, 7 months
seen 2 days ago

Currently a graduate student in mathematics at the University of California - Berkeley.

Previously obtained a MASt. in Applied Mathematics from the University of Cambridge (2013), and a B.S. in Mathematics and a B.A. in Physics from the University of Chicago (2012).


Sep
3
answered A rock connected to one end of string in circular motion gets released.. and what happens?
Sep
2
comment Divergence of One and Two Graviton Exchanges
Are you assuming that the particle is a scalar, so that the interaction is of the form $\partial ^\mu \phi \partial ^\nu \phi g_{\mu \nu}$? This is the only way I could see you getting momenta coming into what appears to be your vertex factors. But if my dimensional analysis is correct, $[\partial ^\mu \phi \partial ^\nu \phi g_{\mu \nu}]=L^{-4}$, so that the corresponding coupling constant would be dimension-less, and in particular, could not be proportional to $1/M_P$. What's going on?
Sep
2
revised Divergence of One and Two Graviton Exchanges
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Sep
1
comment Vacuum Expectation Value and the Minima of the Potential
. . . In practice, you do this by writing the Lagrangian in terms of $\phi :=\phi _0-v$, where $v$ is some minimum of the potential and $\phi _0$ is the original field. My question could then be equivalently phrased as "Why does this guarantee that $\langle 0|\phi (x)|0\rangle =0$?".
Sep
1
comment Vacuum Expectation Value and the Minima of the Potential
@MichaelBrown Indeed, I was under the impression that you had to have this as a re-normalization condition in order to apply LSZ (that is, a hypothesis require for the LSZ Reduction Formula to hold was that $\langle 0|\phi (x)|0\rangle =0$). In fact, I thought this was the entire idea behind the symmetry breaking: you must re-write your Lagrangian in terms of the re-normalized field (with vanishing VEV), and if the bare field had a non-vanishing VEV, this will 'break' the symmetry . . .
Sep
1
comment Vacuum Expectation Value and the Minima of the Potential
So then what is the proof of this leading-order approximation?
Sep
1
asked Divergence of One and Two Graviton Exchanges
Aug
31
asked Vacuum Expectation Value and the Minima of the Potential
Aug
31
revised The vacuum in quantum field theories: what is it?
Expanded the question
Aug
31
revised The vacuum in quantum field theories: what is it?
Expanded the question
Aug
31
asked The vacuum in quantum field theories: what is it?
Aug
29
comment Fine-Tuning, the Hiearchy Problem, and Mass in the Standard Model
@DavidZ You mean the next paragraph in my question? No, that was written by me, included for the purposes of clarifying just what I mean by mass (and what I mean by "my understanding of mass") in this context (as opposed to, for example, just some coefficient in the Lagrangian).
Aug
29
asked Fine-Tuning, the Hiearchy Problem, and Mass in the Standard Model
Aug
21
awarded  Popular Question
Aug
6
revised How do I find constraints on the Nambu-Goto Action?
added 85 characters in body
Jun
8
awarded  Popular Question
May
27
accepted Noether charge of local symmetries
May
27
revised Noether charge of local symmetries
added 14 characters in body
May
27
asked Noether charge of local symmetries
May
14
revised How do I find constraints on the Nambu-Goto Action?
deleted 21 characters in body