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bio website berkeley.academia.edu/…
location Berkeley, CA
age 24
visits member for 2 years, 11 months
seen 16 hours 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).


Dec
7
comment Why quantum mechanics?
@juanrga I was trying to demonstrate what I meant when I originally said "Make as little use of experiment as possible.". What I really meant was "When you make use of experiment, use it to justify as fundamental results as possible". In principle, you would reduce kinetic theory to even more fundamental physics, and so on, and eventually you would get to the point where you couldn't reduce things theoretically anymore, the only thing you could do is justify your assumptions on the basis of experiment, as opposed to just more theory.
Dec
7
revised Why quantum mechanics?
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Dec
5
awarded  Announcer
Dec
5
comment Why quantum mechanics?
@dmckee No, that wasn't really what I was thinking of. I already have an abstract formulation in mind: the usual Hilbert space formulation in which states are elements of the space and observables operators on it. If all you were aware of is classical mechanics, no one in their right mind would guess that's how things should work. Are there a couple of fundamental physical principles that we can make use of that could convince a student who had never seen any of this before that this formulation is in fact quite natural.
Dec
5
comment Why quantum mechanics?
In the Weinberg example, he takes a couple of assumptions that we feel are relatively fundamental and in principle verifiable by experiment (Loretnz invariance of the $S$-matrix and Cluster Decomposition Principle), and uses them to show that the concept of a field naturally arises as a result of demanding the interaction be of a particular form (which itself is dictated by the assumptions). I would like to see an argument that utilizes just a few physical principles to justify the usual Hilbert space formulation of quantum mechanics.
Dec
5
comment Why quantum mechanics?
@EmilioPisanty Essentially, yes.
Dec
5
revised Why quantum mechanics?
added 136 characters in body
Dec
5
comment Why quantum mechanics?
See edit to question. Obviously, you'e going to have to appeal to experiment somewhere, but I feel as if the less we have to reference experiment, the more eloquent the answer would be.
Dec
5
revised Why quantum mechanics?
added 427 characters in body
Dec
5
comment Why quantum mechanics?
As an example of motivation that would satisfy me, the arguments that Weinberg makes in the first part of his first volume to motivate the introduction of quantum fields, while not a proof that nature has to be explained by a field theory, is more than satisfactory if all one seeks is justification to believe that a quantum field theory can be used to describe the universe.
Dec
5
asked Why quantum mechanics?
Dec
5
awarded  Constituent
Dec
5
awarded  Caucus
Nov
8
accepted What is the role of the vacuum expectation value in symmetry breaking and the generation of mass?
Nov
8
comment What is the role of the vacuum expectation value in symmetry breaking and the generation of mass?
I don't quite see how the requirement that you not have a linear term requires us to make the substitution $\psi :=\phi -|v|$. For example, the trivial substitution $\psi := \phi$ doesn't have a linear term, but this can't be correct, because we don't see a massless particle and antiparticle pair, we see a Goldstone boson and a massive real scalar particle.
Nov
8
asked What is the role of the vacuum expectation value in symmetry breaking and the generation of mass?
Oct
30
comment Is the density operator a mathematical convenience or a 'fundamental' aspect of quantum mechanics?
Perhaps I could rephrase my question as "Does there exist a quantum system that exists in reality which cannot be mathematically described by a pure state?". According to your answer, it seems that the answer is "Yes" and that an example is given by "open quantum systems". What exactly do you mean by this and how are they not described by pure states?
Oct
30
comment Is the density operator a mathematical convenience or a 'fundamental' aspect of quantum mechanics?
@A.O.Tell Can you elaborate on what exactly you mean by "representing states of tensor factor subsystems"?
Oct
30
asked Is the density operator a mathematical convenience or a 'fundamental' aspect of quantum mechanics?
Oct
18
awarded  Notable Question