Recent content by iorfus

Sorry for the late answer. Actually, I now think that all the reasoning should be done in ideal conditions, without friction and reaction force. Indeed, in the example gave $$A(-\sqrt{3}, 0); \hspace{0.3cm} B(\sqrt{3}, 0); \hspace{0.3cm} C(0,1),$$ the resultant force on the minimum...

Okay, I see ... I had thought about it too (adding a new point afterward) and it did not help me. You are right, there is a lot of stuff out there. I read some papers and took a look at many\ others. None of them helped me, because I just need to prove that 1-The solution exists (I did it...

First of all, thanks for the answer and for the didactic questions. It precisely tells me that the resultant force is zero, because the two components of the gradient are the horizontal and vertical component of the resultant force acting on the optimal point. I had thought about eliminating...

Anyone? Any hint?

Homework Statement I have to prove some things on the Weber-Ferma problem. Here is the assignment : We want to find a point $$x$$ in the plane whose sum of weighted distances from a given set of fixed points $$y_1, ...,y_m$$ is minimized. 1-Show that there exist a global mimimum to the...

Thanks anyway, DEvens :-) Thank you very much, Mentz114, I am going to take a look at it!

I see, thanks very much. Yes, I am sure (as I was already) I am not goint to make a scientific discovery in my master thesis! It seems to me that the first examples you gave me are in the domain of Astrophysics. Whereas, you also talked about early universe cosmology. Can you give me some...

Hello! I am a master student, and I am about to start working on my master thesis, which, in my counrty, is a substantial work of 6 months which usually involves original research. I will be supervised by two professors of Statistical Mechanics, who have many research interest. In these days...

Thanks!

Maybe it is simply the definition that the dimension of a representation is the dimension of the vector space on which it acts?

Perfect! Last thing: Is this a matter of definition/convention (isomorphisms between Rn and the groups of matrices, etc. ) or is there a "reason" for that?

Thanks! So far so good. Maybe my next questions betrays a more fundamental problem in my comprehension of the subject. To each group element we associate the number 1. Okay. So what does it mean to say that tha modulus of a vector, say (1,1,0) which is 2, is a scalar? I just know that this is...

Hi to all the readers of the forum. I cannot figure out the following thing. I know that a representation of a group G on a vector spaceV s a homomorphism from G to GL(V). I know that a scalar (in Galileian Physics) is something that is invariant under rotation. How can I reconcile this...

Fine. This forum is useful I should start contributing to it in the areas I am knowledgeable about.

I have a last question that I am not able to solve reading books and all the material on the Internet. In the EPR based protocol for QKD, devised by Ekart, are the "no-cloning theorem" and the £indistinguishability of non-orthogonal quantum states£ expoloited? If yes, how? In my...