Science > Physics > Quantum Gravity 228.0: Delay Logistic Star Formation Equation
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Science > Physics |
| User: |
"OsherD" |
| Date: |
24 Jan 2008 12:27:27 AM |
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Quantum Gravity 228.0: Delay Logistic Star Formation Equation |
From Osher Doctorow
Since Probable Causation/Influence (PI) has the Riccati Differential
Equation as its main equation, it is arguably interesting that Alice
C. Quillen and Joss Bund-Hawthoru of respectively U. Rochester New
York and U Sydney Australia have a delayed logistic equation for star
formation in "When is star formation episodic? A Delay differential
equation 'negative feedback' model," arXiv: 0801.3469 v1 [astro-ph] 22
Jan 2008.
I'll let Readers look at this and point out that the delayed feedback
equation with delay tau is:
1) dx/dt = f(x, t) = Aexp(x(t - tau)/C) - B x(t)^(alpha)
which belongs to the class of 1-dimensional equations with delayed
negative feedback including delayed logistic equations, Lasota-
Wazewska model for survival of red flood cells in their 1988 paper,
etc.
Osher Doctorow
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| User: "OsherD" |
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| Title: Re: Quantum Gravity 228.0: Delay Logistic Star Formation Equation |
24 Jan 2008 12:33:38 AM |
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From Osher Doctorow
The logistic differential equation is of course the special case of
the Riccati differential equation with y and y^2 terms having
identical constant coefficients and usually no constant term.
Osher Doctorow
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| User: "OsherD" |
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| Title: Re: Quantum Gravity 228.0: Delay Logistic Star Formation Equation |
24 Jan 2008 12:35:47 AM |
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From Osher Doctorow
I meant to say identical in magnitude constant coefficients, though
one is actually the negative of the other.
Osher Doctorow
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| User: "OsherD" |
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| Title: Re: Quantum Gravity 228.0: Delay Logistic Star Formation Equation |
24 Jan 2008 12:42:57 AM |
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From Osher Doctorow
The second author of the paper cited was misspelled, and should be:
Joss Bland-Hawthorn.
Osher Doctorow
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