user10001

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A Sufi prayer of love

O love, O pure deep love, be here, be now, be all.

Dissolve me into your stainless endless radiance,

Make me your servant, your breath, your core.
                   :- by sufi mystic Rumi

	689 reputation	bio	website	en.wikipedia.org/wiki/…	visits	member for	11 months
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Apr 30	comment	Vortex in D dimensions soliton It would help if you mention the source from which you borrowed fig 3.1.
Apr 29	comment	How is the hamiltonian a hermitian operator? For a mathematically rigorous formulation of QM one needs notion of rigged Hilbert spaces. However most of the physicists who use QM as a tool to understand nature usually don't try to be too rigorous(I myself have never read the wiki page I referred to:).
Apr 17	revised	When can a global symmetry be gauged? added 22 characters in body
Apr 17	answered	When can a global symmetry be gauged?
Apr 9	comment	Does the mass point move? Nice question +1. However it should be noted that (in framework of classical mechanics) only specification of the initial conditions is not enough to find out time evolution of an entity. One should also specify the force.
Apr 1	comment	exponential potential quantization Did you mean $e^{bx}$ ?
Mar 22	revised	A simple model that exhibits emergent symmetry? Included latex
Mar 22	suggested	suggested edit on A simple model that exhibits emergent symmetry?
Mar 14	awarded	Organizer
Mar 14	revised	Did Hilbert publish general relativity field equation before Einstein? edited tags
Mar 13	comment	Renormalization: Why is only a finite number of counter-terms allowed? As Josh answered a theory is called renormalizable if it requires only a finite number of counter terms for canceling infinities. Initially it was thought that non-renormalizable theories are in some sense bad in that they have no predictive power. However nowadays such theories too are seen with respect and are studied as "effective field theories". But still most physicists believe that a fundamental theory of nature should have the property of renormalizability. Here by fundamental I mean a theory written in terms of fundamental entities i.e those which can not be broken into smaller ones.
Mar 10	comment	commutation of operator product expansion @Barefeg I made some changes. Actually you can conclude from two equations that O_2 and O_1 are equal.
Mar 10	revised	commutation of operator product expansion added 44 characters in body
Mar 9	answered	commutation of operator product expansion
Mar 5	comment	A universe of angular momentum? Relevant: is-all-angular-momentum-quantized?
Mar 5	comment	A universe of angular momentum? @JohnRennie Sorry I didn't know that. Do you mean angular momentum observables can have states with continuous eigenvalues?
Mar 5	comment	A universe of angular momentum? @Cheeku Observables in QM are matrices rather than functions so they do not commute in general(ie AB=!BA). In more simple terms suppose S is a physical system (say a particle) and A and B be two (quantum) observables associated with S. Say A= position and B=momentum. Now to know the value of A and B you have two choices - i) first measure A and then measure B ii) first measure B and then measure A. Classically both the ways are equivalent and will give the same result while for quantum systems these two ways of measurement are in general not equivalent and give different values of A and B.
Mar 5	comment	A universe of angular momentum? However real essence of QM is not in the fact that angular momentum takes discrete values but in the fact that observables generally don't commute (whereas in classical mechanics they always commute).
Mar 5	comment	A universe of angular momentum? Angular momentum is the most basic observable where QM differs from classical mechanics. In QM angular momentum takes only discrete values whereas (unless the particle is trapped in a finite region of space) momentum and position take continuous values in QM just as in classical mechanics.
Feb 21	comment	In what sense is a scalar field observable in QFT? @user1504 I always had the viewpoint that observables have to do with symmetry of the theory. They form a representation of symmetry group on space of states. We can work in terms of fields or creation - annihilation operators or may be something else. The physical content of the theory is not in fields but in the space of states and the representation of the symmetry group on it.