Bifurcations and Center Manifold

  • Thread starter Thread starter Rubik
  • Start date Start date
  • Tags Tags
    Center Manifold
Rubik
Messages
95
Reaction score
0

Homework Statement



If β=0 the neurone model is \dot{u}= -u
\dot{v}= v2 + v - u + \delta
If \delta = 1/4 it has critical point (0,-1/2)

Transform the system so that the critical point is at the origin so let \bar{v} = v +1/2 and find the equations of motion for (u,\bar{v})

Homework Equations





The Attempt at a Solution



Does this mean for a change of variables I let \bar{u} =u and \bar{v}= v + 1/2 subs in gives

\dot{u} = \bar{u}
\dot{v} = \bar{v}2 + \bar{u}

Is that all I have to do?
 
Physics news on Phys.org
Rubik said:

Homework Statement



If β=0 the neurone model is \dot{u}= -u
\dot{v}= v2 + v - u + \delta
If \delta = 1/4 it has critical point (0,-1/2)

Transform the system so that the critical point is at the origin so let \bar{v} = v +1/2 and find the equations of motion for (u,\bar{v})

Homework Equations





The Attempt at a Solution



Does this mean for a change of variables I let \bar{u} =u and \bar{v}= v + 1/2 subs in gives

\dot{u} = \bar{u}
\dot{v} = \bar{v}2 + \bar{u}

Is that all I have to do?

No. You have a system in terms of v and u and you want to represent that system in terms of new variables which have a critical point at the origin so you can study the system for small changes of t near the origin. If I let say w=v+1/2, then w'=v' and v=w-1/2. Now, in terms of u and w, the first one is unchanged but what is w' in terms of u and w:

u'= u
w'=
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top