Bifurcation Definition and 47 Threads

  1. HansBu

    Periodic and Chaotic Solutions to Chen System/Attractors

    Here is the Chen System I am given the initial condition (t=0) that a particle lies on the xyz-plane at a point (-10,0,35). I was notified that if I plugged in a=40, b=5, and c=30, the trajectory of the particle will be chaotic. On the other hand, if I retained the values of a and c, and...
  2. Decimal

    A Path between fixed points in a logistic map

    Hello, I have a question about period doubling and fixed points in the logistic map. Let's say I have a basic logistic map, ##f(x) = 4\lambda x(1-x)##. Let me then compare 1,2 and 4 iterations of this map on fixed points. I assume that ##\lambda## is large enough such that two period doublings...
  3. DaveC426913

    B The Mandelbrot Set has a third dimension: the Bifurcation Diagram

    This is wild. I was always fascinated with the Mandelbrot set, as well as the bifurcation diagram. I had no idea the Mandelbrot diagram was a different visualization of the bifurcation diagram. Question: is this video accurate? I always question the veracity of YouTube science videos.
  4. M

    I Using a bifurcation diagrams and time dependent parameters

    Hello, I'm lost at where to go after drawing bifurcation diagram of $$\dot{x} = r + x - x^3.$$ If we also assume our parameter is time dependent such that $$\dot{r} = -\delta x.$$ How could we use our initial bifurcation diagram to sketch solutions for small δ?
  5. Jezza

    I Physical examples of different types of bifurcation

    I have to sit an exam on non linear dynamical systems in a couple of weeks. Something that's been asked in the past is to name physical examples of different types of bifurcation. I've consulted Strogatz's book and the internet to try and find some, but I can't seem to find many (or even any)...
  6. U

    Applied Book recommendations for Bifurcation Diagrams

    Hello my friends, I am studying excitability in quantum dot lasers and I see a lot of bifurcation diagrams with saddle node bifurcations, Hopf bifurcations, homoclinic bifurcations, PD bifurcations etc. I know some basic things about non-linear systems but I have never met the notion of...
  7. S

    Can subharmonics in a system be also termed as bifurcation?

    I think that the existence of subharmonics is also bifurcation.Is that true
  8. S

    Difference between bifurcation and chaos

    Chaos is when the waveforms become aperiodic. I think bifurcation is the phenomenon inclusive of chaos and in addition, it is also termed for situations in which the waveforms become n-periodic.Does bifurcation include period-n phenomenon as well as chaos? From period-n it means that still the...
  9. L

    I Critical value of homoclinic bifurcation

    Hello, I hope to find some help. I have equation: and I need to find the value of parameter A at which the homoclinic bifurcation occurs. I know, that in this case A=-0.34, but I solution, how to find it. Can you help me, what numerical method I should use to find A? Thank you very much.
  10. S

    Why is chaos more studied in dc-dc converters compared to other circuits?

    Why is chaos only more studied in dc-dc converters and not in other nonlinear circuits, such as, rectifiers?
  11. M

    A How Does the Bifurcation Diagram in AUTO Represent Mathematical Concepts?

    Hi PF I am given the ODE ##\ddot{\theta} +q\sin\theta+\mu\cos\theta=0##, where I introduce ##x_1 = \theta## and ##x_2=\dot{\theta}## to yield$$ \dot{x_2}=-q\sin x_1-\mu\cos x_1\\ x_2=\dot{x_1} $$ subject to ##x_2(0)=x_2(1)=0## and ##\int_0^1\sin x_1\, d t = 0##. I then plug this system into...
  12. JuanC97

    What conditions are needed to get a stable limit cycle here?

    Homework Statement I want to find conditions over A,B,C,D to observe a stable limit cycle in the following system: \frac{dx}{dt} = x \; (A-B y) \hspace{1cm} \frac{dy}{dt} = -y \; (C-D x) Homework Equations Setting dx/dt=0 and dy/dt=0 you can find that (C/D , A/B) is a fixpoint. The Attempt...
  13. P

    What is the word for bifurcation but with multi-branching?

    I thought it would be polyfurcation but it s not in dictionary. Also if blood vessels use venturi effect to lower pressure in some places, what is the extra speed used for?
  14. onkel_tuca

    Bifurcation between two oscillations

    Hello world! I've done a few simulations of an emulsion droplet which is actuated by a laser beam. The droplet starts to move due to the laser light. I don't want to talk too much about the physics behind this but more discuss the nonlinear dynamics of the trajectories. Depending on a parameter...
  15. U

    Pendulum - Stability and fixed points

    Homework Statement (a): Show the lagrangian derivative in phase space (b)i: Show how the phase space evolves over time and how they converge (b)ii: Find the fixed points and stability and sketch phase diagram (c)i: Find fixed points and stability (c)ii: Show stable limit cycles exist for T>ga...
  16. O

    Proving a a pitchfork bifurcation: modified swift-hohenberg

    I'm trying to solve question 4.12 from Cross and Greenside "pattern formation and dynamics in nonequilibrium systems". the question is about the equation \partial_t u = r u - (\partial_x ^2 +1)^2 u - g_2 u - u^3 Part A: with the ansatz u=\sum_{n=0}^\infty a_n cos(nx) show that the...
  17. F

    Locate any bifurcation in 2D system

    Homework Statement bifurcation for the following 2D system: Homework Equations x'=ux−y+x^3,y′=bx−y The Attempt at a Solution I have got ux−y+x^3=0, y=bx, then x=0 and ±sqrt(b−u). But I don't how to continue to find the bifurcation?
  18. J

    What is the difference between a contour plot and a bifurcation plot?

    On Wolfram Alpha it will offend give you a contour plot, and it has similarities to a bifurcation plot with respect to a variable and a parameter. What is the difference between a contour plot and a bifurcation diagram?
  19. S

    Bifurcation values for logistic map

    Homework Statement Find numerically the r values for the first 2 bifurcations. Homework Equations xi+1 = f(xi), f(x) = rx(1 − x) The Attempt at a Solution To find the values of r, first I set rx(1−x)=0 to find x and then used the x values to find r=0 and r=1. But, I am still...
  20. N

    Differential equation bifurcation, how to find equilibrium points?

    Homework Statement What are the bifurcation values for the equation: dy/dt = y^3 +ay^2 Homework Equations The Attempt at a Solution Equilibrium solutions: y^3 + ay^2 = 0 ==> y^2 (y + a) = 0 ==> y = 0 (double root), or y = -a. a = 0 is the sole bifurcation point, since...
  21. J

    Bifurcation point of x' = r + x/2 - x/(x+1)

    Homework Statement As in title. Homework Equations My book has a very shaky definition of what a bifurcation point. Basically, I need to play around with r and see how the system changes. The Attempt at a Solution x' = 0 when x = 1/2 - r ± √((r-1/2)2 - 2r) d/dx (x') = 1/2 -...
  22. J

    Bifurcation Points and Stability Analysis for x' = x(r - ex)

    Homework Statement Just making sure I understand this stuff. One question on my homework asks about x' = x(r - ex). Homework Equations Definition. From my textbook: "The qualitative structure of the flow can change as parameters are varied. In particular, fixed points can be created or...
  23. C

    Hopf Bifurcation - Nonlinear Diff Eqns

    Homework Statement http://www.freeimagehosting.net/t/9369y.jpg Homework Equations The Attempt at a Solution a) is as follows: http://www.freeimagehosting.net/t/4oqft.jpg Then for b), I have the equilibria as (0,0,0) and (r-1,\frac{r-1}{r},\frac{(r-1)^2}{r}) To...
  24. P

    Drawing Bifurcation diagrams for a dynamical system

    1. Homework Statement [/b] Consider the dynamical system \frac{dx}{dt}=rx-\frac{x}{1+x} where r>0 Draw the bifurcation diagram for this system. Homework Equations The Attempt at a Solution Well fixed points occur at x=0,\frac{1}{r}-1 and x=0 is stable for 0<r<1 and unstable for...
  25. A

    Find all bifurcation points (ODEs)

    I'm at a loss on this question...my troubles seem to be algebraic or that I'm simply missing something.x' = \mu - x2 +4x4 my method for these questions has basically been to do everything required to draw bifurcation diagram bar drawing the actual diagram itself (ie, find equilibria, what...
  26. J

    MHB ODE system. Limit cycle; Hopf bifurcation.

    Problem: The following two-dimensional system of ODEs possesses a limit-cycle solution for certain values of the parameter$a$. What is the nature of the Hopf bifurcation that occurs at the critical value of $a$ and state what the critical value is. $\dot{x}=-y+x(a+x^2+(3/2)y^2)$...
  27. S

    Bifurcation Analysis for the ODE x' = \mux - x2 + x4

    Homework Statement Consider the ODE x' = \mux - x2 + x4 where x \in R and \mu \in R is a parameter. Find and identify all bifurcation points for this equation. Sketch a bifurcation diagram, showing clearly the stability of all equilibria and the location of the bifurcation points. You may...
  28. G

    Solve Bifurcation Diagrams: Find Critical Values of r

    Homework Statement For each of the following equations sketch the bifurcation diagram, determine type of bifurcation, and find the critical value of r. ẋ = rx + cosh(x) ẋ = x(r - sinh(x)) ẋ = rx - xe-x2 The attempt at a solution Fixed points satisfy f'(x) = r + sinh(x) = 0 ⇒ x* =...
  29. G

    Subcritical Pitchfork Bifurcation

    Homework Statement Consider the system dx/dt = rx + x^3 - x^5, which exhibits a subcritical pitchfork bifurcation. a) Find algebraic expressions for all the fixed points. b) Calculate r_s, the parameter value at which the nonzero fixed points are born in a saddle-node bifurcation. The...
  30. P

    Where Does Homoclinic Bifurcation Occur in a 2-D Nonlinear Dynamics System?

    Hi everyone, I am studying a 2-D nonlinear dynamics system, with two key parameters. But I have trouble when I want to locate where the homoclinic bifurcation occurs in the parameter space. Can anyone give me some ideas or reference readings? Thx
  31. S

    Understanding Bifurcation Points in the Function dy/dt = y^3 + ay^2

    Can anyone help me find the bifurcation value of dy/dt = y^3 + ay^2 where a is the parameter. I found that the bifurcation value is 0 but at that equilibrium point the phase graph shows a source, not a node, so I'm not totally sure. Someone help please!
  32. J

    Mathematica Solving Real Roots with NSolve and Plotting a Bifurcation Diagram

    Hi, I'm using NSolve in Mathematica but I only want to find the roots that are real numbers as my answer gives a lot of imaginary numbers. How can I do this? I want to then plot a birfucation diagram using a table of data. Is there a function to do this? Thanks!
  33. J

    Mathematica Produce a bifurcation diagram using mathematica

    I want to produce a bifurcation diagram using mathematica to represent equilibrium points of p1 using the data obtained from the following code, where pn1, pn2, pn3 are recrusion exquations. i.e. x-axis will be the paramter t (ranging from 0-0.3) and y-axis will be the values of p1 this code...
  34. G

    How Does Bifurcation in Dynamical Systems Influence Information Generation?

    I would like to ask for a piece of advice on references on following issue: Any (macroscopic) bifurcation of dynamical system generates some new information (or loss of information). In particular, when the dynamical system is loosing stability (i.e. stable equilibria becomes unstable) some new...
  35. C

    Differential Equation - Bifurcation

    Homework Statement The following model describes a fox population: \frac{dS}{dt} = kS(1 - \frac{S}{N})( \frac{S}{M} - 1) a) at what value of N does a bifurcation occur? b) How does the population behave if the parameter N slowly and continouly decreases towards the bifurcation value...
  36. D

    Bifurcation Diagram <Diff. Eqns>

    Homework Statement Draw the bifurcation diagram for the following equation. :attached: Homework Equations I believe this is a population D.E. The Attempt at a Solution I'm ashamed to say I'm at a complete loss with this problem. The only step I'm familiar with is finding the...
  37. nicksauce

    Van der Pol oscillator + Hopf bifurcation

    Homework Statement Consider the biased van der Pol oscillator: \frac{d^2x}{dt^2}=u (x^2-1)\frac{dx}{dt} + x = a. Find the curves in (u,a) space at which Hopf bifurcations occur. (Strogatz 8.21) Homework Equations The Attempt at a Solution Not even sure where to start with this...
  38. S

    Finding the Hopf Bifurcation in the FitzHugh Model

    Hello all, i was given the following assignment: FitzHugh proposed the dynamical system \dot{x}=-x(x-a)(x-1)-y+I \dot{y}=b(x-\gamma y) to model neurons. I is the input signal, x is the activity, y is the recovery and 0<a<1, \gamma>0, b>0 are constants. Prove that there is a critical...
  39. Evo

    Believing Scripture & Pursuing Science: The Bifurcation of the Mind

    Let's keep this about the subject. This isn't about religion, but about people believing in one thing (creationism) and pursuing an advanced scientific degree. Some say it is for carrying the "legitimate" degree in order to give credibility to creationism and shouldn't be allowed if they...
  40. I

    Is there a mathematical way to calculate the bifurcation of a system?

    Is there a mathematical way to calculate the bifurcation of a system?
  41. H

    Convection described by Lorenz's Equation Bifurcation

    Hi all! I am currently reading the text "Practical Bifurcation and Stability Analysis" by Seyedel for an introduction to practical bifurcation theory. I do not tatolly understand the theory and hope that some of you could help explain to an idiot like me. I have read till P.80 of the books...
  42. B

    Bifurcation and Stability of Equilibria

    When determining the stability of the equilibria (or, critical points) for our bifurcation diagrams, we have been shown to use phase line diagrams. I understand that if the function is moving away from the equilibria on either side than it is unstable, and i know that if the function is...
  43. N

    Perturbation vs Bifurcation Theory

    I know what Bifurcation Theory is. but What is Perturbation theory? is it similar to bifurcation theory?
  44. L

    What is a bifurcation surface and a binormal vector?

    I've been reading Wald's book on GR as well as his article "Thermodynamics of Black Holes" in Living Reviews in Relativity about the definitions of mass and energy in GR and the concepts of entropy and temperature of black holes. I keep coming across the words "bifurcation surface" and...
  45. D

    Bifurcation Points - Differential Equations

    "Bifurcation Points. In many physical problems some observable quantity, such as a velocity, waveform, or chemical reaction, depends on a parameter describing the physical state. As this parameter is increased, a critical value is reached at which the velocity, or waveform, or reaction suddenly...
  46. Z

    What Is a Bifurcation Diagram and How Do You Create One?

    Could some explain or point me to somewhere explains what a Bifurcation Diagram is and how to draw one given a non-linear function. Got an exam today and nobody knows what one is. If it has already been 2 hours after I've posted this don't worry, I'll be heading off to the exam hehe. Thanks if...
  47. Loren Booda

    Under what conditions does star bifurcation occur?

    Under what conditions might a star bifurcate?
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