Loops Definition and 275 Threads

From Trees to Loops and Back Andreas Brandhuber, Bill Spence, Gabriele Travaglini 49 pages, 17 figures http://www.arxiv.org/abs/hep-th/0510253 We argue that generic one-loop scattering amplitudes in supersymmetric Yang-Mills theories can be computed equivalently with MHV diagrams or with...

"Loops" has become a defacto provisional collective name for all the main efforts to get a nonperturbative backgroundindependent theory of QG. If these approaches are going to coalesce into one broad field of research and have an annual meeting, should it be called Loops '06 like it was this...

http://atdotde.blogspot.com/2005/10/others.html Robert Helling is a string theorist. He is winning the gratitude-for-life of many Loop-fans by blogging live from the Albert Einstein Institute at Potsdam-Golm. Non-perturbative/background independent QG people are, for him, "the Others"...

Dear every one, I'm studying on micromagnetics problem using Brown's equation for static solving case, this equation derived from minimization of energy and it allows us to obtain a hysteresis loop of a magnetic material. All of my documents only say that from Brown's equation, we can...

http://loops05.aei.mpg.de/ it's out

in this page I've encountered this topic (it's a topic from combinatorics, so it's relevant to discrete maths with sets and so on [that's my justification to post it here o:) ), anyway from my point of view the page describes poorly the successor operation: "The resulting sequence of...

In doing my \phi^{3} theory I didn't know exactly how to count the number of loops in a diagram given the number of vertices, internal and external lines. Is there a general algorithm in doing this? What if we have more than one interaction vertex (e.g. the Standard Model)? PS. What does it...

How does one prove that the curve r=sin(n{theta}) has n loops when n is odd and 2n loops when n is even?

http://loops05.aei.mpg.de/index_files/Home.html October 10-14 at Potsdam, Albert Einstein Institute The aim of this conference is to summarise the status and open problems of the various approaches to quantum gravity and to present new ideas and research directions. "The topics of this...

I've been having trouble with the solution my book (and the solution manual) gives for a problem. Basically, there are two inductors (wire coils): one is on the left, hooked to a battery and a switch. Then there's one to the right of it, hooked to only a resistor. The left switch is closed...

If I generate current through two identical loops (parallel) of transformer wire in the same direction, why do they produce an uniform magnetic field at the centre of the space between the loops ONLY IF the separation distance between the loops is equal to the radius of each coil? and not if...

Is there someone out there who could explain string theory and loop quantum gravity to me in plain English, please? I have no mathematical ability whatsoever, so I'm looking for an explanation of the concepts. Numbers leave me scratching my head. I am not suggesting that my numerical stupidity...

I'm trying to use the improved euler method to calculate the position vector of a rocket on a mission from the Earth to the moon. The method involves calculating new values of acceleration whilst time is incremented and using this IN ADDITION to the previous values of acceleration to find the...

Hi, I'm just wondering if anyone knows how I should be setting up my FBD for this question, or any hints as to how to go about doing this question: "A long piece of wire with a mass of 0.100 kg and a total length of 4.00 m is used to make a square coil with a side of 0.100 m. The coil is...

I am working on a little piece of a program that prints two diagonal lines. I am using a variable "num" to specify how far down to draw each diagonal. What I would like to do is be able to start at a position on the screen and have the printing begin at that position, and also track the...

Question: An aeroplane loops the loop in a verticle circle of radius 200m, with a speed of 40m/s at the top of thel oop. The pilot has a mass of 80kg. What is the tension in the strap holding him into his seat when he is at the top of the loop?. Answer: The centrifugal force...

What is the difference btw 2 conducting loops? Hello. What is the difference between a conducting loop with charge q distributed over the loop that is rotating and a stationary loop with current flowing around the loop? Do they have the same effect when it comes to calculating magnetic...

Hiya, Materials: - Two current loops oscillating at ~ 9GHz Square Wave Orientation: - Stack the two loops one on top of the other at ~ 1cm seperation. What I See: - At that distance and frequency of oscillation it appears as if you could get a force with an equal reaction...

I just got back from the Marseille conference on loop quantum gravity and spin foams: http://w3.lpm.univ-montp2.fr/~philippe/quantumgravitywebsite/ It was really great, so I devoted "week206" of my column This Week's Finds entirely to this conference...

"The Duel: Strings versus Loops" by Rudy Vaas http://arxiv.org./ftp/physics/papers/0403/0403112.pdf it's a 10-page popular article about the Strings meets Loops conference last October written for Bild der Wissenschaft (translated into English by Martin Bojowald and Amitaba Sen) Part...

by faraday's law induced current in a conducting loop is caused by changes in magnetic flux through that loop.. now, if you move a conducting loop through uniform magnetic field (fixed magnitude and direction) there is an induced current even though there is (apparently) no change in magnetic...

I have a homework problem with an RL circuit. There are two loops in the circuit. One has the emf and two resistors and a switch and the other has two resistors and an inductor. The resistors, the inductor and the emf are all given values and I'm given that the switch is closed at time = 0...

consider two conducting loops with fixed geometries and at fixed positions. Let I1 and I2 be the currents flowing in the loops 1 and 2. how does Faraday's Law allow the currents I1 and I2 to affect each other? farday's law says that changing the flux between loops 1 will induce an emf in...

John Baez just posted this announcement and tentative schedule for a conference this month at the Albert Einstein Institute (Max Planck Institute for Gravitation Physics) on the outskirts of Berlin. We have had several threads at PF studying work by AEI people---Hanno Sahlmann, Martin...

It occurred to me that the existence of localized time reversal would manifest an evolution that relies more on free will than genetic determination. The connectivity between two events completing a time loop takes place arbitrarily to Darwinism, either fulfilling spacetime continuity or...