Register to reply

Derivatives of ln of summation

by mmwave
Tags: derivatives, summation
Share this thread:
mmwave
#1
Nov30-03, 06:12 PM
P: 211
Summations and calculus gives me fits so please verify my results on these 2 issues:

1. Z = summation ( exp ( - B*E(s)) ) where the sum is over s

d/dB of ln(Z) = d/dB (ln (exp(-BEo) + exp(-BE1) + ... exp(-BEn))
= (exp(-BEo) + exp(-BE1) + ... exp(-BEn))^-1 +
(-E0*exp(-BEo) + -E1*exp(-BE1) + ... -En*exp(-BEn))

= summation ( E(s) * exp(-B*E(s)) / summation ( exp(-B*E(s))

which is also the average value of E when Prob(E(si)) = exp(-BE(si))

2. does d/dT of exp( -E/kT) = -E/k * exp(-E/kT) * -(1/T^2) =
E/k* 1/T^2 * exp(-E/kT) ?


If you're curious, these come up in Boltzmann statistics in thermal physics.
Phys.Org News Partner Science news on Phys.org
New type of solar concentrator desn't block the view
Researchers demonstrate ultra low-field nuclear magnetic resonance using Earth's magnetic field
Asian inventions dominate energy storage systems
Ambitwistor
#2
Nov30-03, 06:52 PM
P: 837
Looks fine to me.
Physcello
#3
Nov16-11, 04:31 PM
P: 2
Hi, where did the last term come from in 2nd question?
Also i want to ask what is d/d(ni)[summation(ni*ln(ni))]? i:from 1 to r.
ni is n sub indice i


Register to reply

Related Discussions
Summation x(1/2)^x Calculus & Beyond Homework 2
Help with summation Calculus & Beyond Homework 10
Summation equation help Calculus & Beyond Homework 9
Rewrite the following sum with the index of summation General Math 8
Summation help Classical Physics 0