Statistical mechanics. Partition function.

LagrangeEuler
Messages
711
Reaction score
22

Homework Statement


If ##Z## is homogeneous function with property
##Z(\alpha T,\alpha^{-\frac{3}{\nu}}V,N)##
and you calculate Z(T,V,N). Could you calculate directly ##Z(\alpha T,\alpha^{-\frac{3}{\nu}}V,N)##.


Homework Equations


##Z(T,V,N)=\frac{1}{h^{3N}N!}(2\pi m k T)^{\frac{3N}{2}}\int...\int_{V} e^{-\frac{U}{kT}}##



The Attempt at a Solution


When I have for exaple
##Z(\alpha T,\alpha^{-\frac{3}{\nu}}V,N)=\frac{1}{h^{3N}N!}(2\pi m k \alpha T)^{\frac{3N}{2}}\int...\int_{\alpha^{-\frac{3}{\nu}}V} e^{-\frac{U}{k\alpha T}}##
I'm not sure how to integrate this ##e^{-\frac{U}{k\alpha T}}## in exponent.
[
 
Physics news on Phys.org
From this if I understand well
##\int...\int_{\alpha^{-\frac{3}{\nu}V}}e^{-\frac{U}{k\alpha T}}##
need to be equal
##\int...\int_{\alpha^{-\frac{3}{\nu}V}}e^{-\frac{U}{k\alpha T}}=\alpha^{-\frac{3N}{\nu}}...##
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
Back
Top