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1 vote
0 answers
110 views

Long term behavior of a nonlinear dynamic system

Consider the following system of first order nonlinear difference equation: $$ \begin{cases} x_{k+1} = x_k + \alpha(1-x_ky_k^2) \\ y_{k+1} = y_k + \alpha(1-x_k^2y_k) \\ \end{cases} $$ with a given ...
William's user avatar
  • 997
3 votes
1 answer
271 views

Given $(a_n)$ such that $a_1 \in (0,1)$ and $a_{n+1}=a_n+(\frac{a_n}{n})^2$. Prove that $(a_n)$ has a finite limit. [duplicate]

Given $(a_n)$ such that $a_1 \in (0,1)$ and $a_{n+1}=a_n+(\frac{a_n}{n})^2$. Prove that $(a_n)$ has a finite limit. Clearly $a_n$ are increasing. Also, $$\frac{1}{a_{n+1}}=\frac{1}{a_n\left(1+\frac{...
nitu das's user avatar
0 votes
1 answer
197 views

Time Scale Calculus/Dynamic Equations on Time Scales

Studying the mathematics of dynamic phenomena seems to branch out in an overwhelming number of directions. There are univariate and multivariate varieties, continuous and discrete varieties, ...
user10478's user avatar
  • 1,922
4 votes
1 answer
94 views

If $x_{n+1}=x_n+x_n^{-m}, x_1>0, m \ge 2 $ then $x_{n}^{m+1} = (m+1)(n+\ln(n))+O_m(1) $

This is a generalization of Divergence of a sequence proof Show that if $x_{n+1}=x_n+\dfrac{1}{x_n^m}, x_1>0, m \ge 2 $ then $x_{n}^{m+1} = (m+1)(n+\ln(n))+O_m(1) $. (Note: The notation $O_m(...)$ ...
marty cohen's user avatar
0 votes
1 answer
915 views

How to determine the stability of a fixed point if the derivative at the point is equal to one? ($\,\left\lvert\, f'(x^{\ast})\right\rvert = 1$)

Context: I am learning about 1-dimensional maps: For instance the logistic model of population growth. Suppose I have the map $x_{n+1} = f(x_n)$. The point $x^{\ast}$ is called a fixed point of the ...
Conor Cosnett's user avatar
2 votes
2 answers
132 views

Tight upper bounds for a monotonically increasing non-linear recurrence

I have the following non-linear recurrence: $$y_{n+1} = \sqrt{\frac{2}{1+y_n}}y_n,\quad y_0 \in[0,1]$$ Some basic thought shows that $0$ and $1$ are fixed points of this, and that $0$ is repelling ...
Mark Schultz-Wu's user avatar
4 votes
2 answers
199 views

Solving the recurrence relation $y_{n+1}=y_n+a+\frac{b}{y_n}$

I am hoping to obtain a closed-form solution or an asymptotic result for the recurrence relation $$y_{n+1}=y_n+a+\frac{b}{y_n}$$ Any help would be very much appreciated!
Alex's user avatar
  • 383
0 votes
1 answer
229 views

Can a 2 cycle occur in logistic map for r=4?

In web page http://mathworld.wolfram.com/LogisticMap.html it's written that for $$x_{1,2}=\dfrac{1}{2} \Bigg[(1+r^{-1}) \pm r^{-1} \sqrt{(r-3)(r+1)} \Bigg] \tag 1 $$ a 2-cycle occurs. Although don't ...
Lena Pappa's user avatar