# Phase Transitions and Critical Phenomena

1. Nov 14, 2009

### Cryphonus

Phase Transitions and Critical Phenomena!!

First 2 questions are not mathematical questions.So if there is someone who knows about what im talking about i would be glad to hear what critical phenomena is about, i know i can use google for it and i actually did. But they are not really useful since they use "Encyclopedia Language".....

1. The problem statement, all variables and given/known data

(a) What is a renormalization-group transformation?
(b) What is the physical significance of a renormalization-group fixed point?
(c) Starting from the relation T’ – TC = λ (T – TC) near the fixed point at TC, derive the
correlation length critical exponent ν occurring in ξ = ξ0 |T-TC| - ν. The length
rescaling factor b of the renormalization-group transformation will occur in your

2. Relevant equations

relevant equations are give in (c)

3. The attempt at a solution
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2. Feb 4, 2010

### kikushiyo

Re: Phase Transitions and Critical Phenomena!!

(a) it is a transformation that rexpresses your physical situation in terms of lower energy degrees of freedom but keeping the same physical content. It is related to a change of observation scale (always from microscopic to macroscopic situation, in this sense it is a semi-group)

(b) a fixed point is when your theory decomes scale invariant i.e. when doing RG transformation, it keeps the same properties.

(c) My god ! You know nothing about RG and you want to have your problem solved ? Go to see the wiki page ! Even there you can find the solution !!!