Differences between revisions 26 and 27
Revision 26 as of 2014-02-15 14:38:44
Size: 7907
Editor: dch252
Comment:
Revision 27 as of 2014-02-15 14:41:09
Size: 10247
Editor: dch252
Comment:
Deletions are marked like this. Additions are marked like this.
Line 28: Line 28:
# -*- coding: utf-8 -*-
"""
Created on Mon Feb 10 20:05:11 2014

@author: David Horgan
"""

from scipy.optimize import fsolve
import math



#scene.range = 10

#cylinder(pos=(0,0,0), radius=1.0,axis=(0,0,1), color=color.white)

#scene2 = display(title='Examples of Tetrahedrons',
    # x=0, y=0, width=600, height=600,
    # center=(0,0,0), background=(1,1,1))

#scene2.visible = True
#scene2.range = 10




#unit circle plot
C = circle((0,0), 1)





#input points from unit circle

p1=0.6
p2=0.7


#face1
a1=(((1 - p2**2)/(2*(1 + p1)))**(1/4), (1/2)*(p2 + 1)*((2*(1 + p1))/(1 - p2**2))**(1/4), 0)
a2=(((1 - p2**2)/(2*(1 + p1)))**(1/4), (1/2)*(p2 - 1)*((2*(1 + p1))/(1 - p2**2))**(1/4), 0 )
a3=(((1/2)*( (1 + p1)**3)* (1 - p2**2))**(1/4),p2*((2*(1 + p1))/(1 - p2**2))**(1/4), sqrt(1 - p1**2)*((1 - p2**2)/(2*(1 + p1)))**(1/4) )
a=[a1,a2,a3]


#face2

b1=(0, 0, 0)
b2=(((1 - p2**2)/(2*(1 + p1)))**(1/4), (1/2)*(p2 - 1)*((2*(1 + p1))/(1 - p2**2))**(1/4), 0)
b3=(((1/2)*((1 + p1)**3)*(1 - p2**2))**(1/4),p2*((2*(1 + p1))/(1 - p2**2))**(1/4), sqrt(1-p1**2)*((1-p2**2)/(2*(1+p1)))**(1/4) )
b=[b1,b2,b3]

#face3
c1=(0, 0, 0)
c2=( ((1 - p2**2)/(2*(1 + p1)))**(1/4), (1/2)*(p2 + 1)*((2*(1 + p1))/(1 - p2**2))**(1/4), 0)
c3=(((1/2)*((1 + p1)**3)*(1 - p2**2))**(1/4), p2*((2*(1 + p1))/(1 - p2**2))**(1/4), sqrt(1 - p1**2)*((1 - p2**2)/(2*(1 + p1)))**(1/4) )
c=[c1,c2,c3]


#face4
d1=(0, 0, 0)
d2=(((1 - p2**2)/(2*(1 + p1)))**(1/4), (1/2)*(p2 + 1)*((2*(1 + p1))/(1 - p2**2))**(1/4), 0)
d3 =(((1 - p2**2)/(2*(1 + p1)))**(1/4), (1/2)*(p2 - 1)*((2*(1 + p1))/(1 - p2**2))**(1/4), 0)
d=[d1,d2,d3]

#printresults
print 'a1=', a1
print 'a2=', a2
print 'a3=', a3

print 'b1=', b1
print 'b2=', b2
print 'b3=', b3

print 'c1=', c1
print 'c2=', c2
print 'c3=', c3

print 'd1=', d1
print 'd2=', d2
print 'd3=', d3



G = Graphics()

#tetrahedron faces - coloured
P1=polygon([a1,a2, a3], color='red')
P2=polygon([b1,b2, b3],color='yellow')
P3=polygon([c1,c2, c3],color='blue')
P4=polygon([d1,d2, d3],color='green')

#polygon faces
#P1=polygon([a1,a2, a3])
#P2=polygon([b1,b2, b3])
#P3=polygon([c1,c2, c3])
#P4=polygon([d1,d2, d3])

#polygon([a1,a2, a3])
#polygon([b1,b2, b3])
#polygon([c1,c2, c3])
#polygon([d1,d2, d3])

g=G+P1+P2+P3+P4
show(g)
show(C)

Sage Interactions - Loop Quantum Gravity

goto interact main page

5-cell.gif

Holomorphic factorization of the Quantum Tetrahedron

by David Horgan.

Moduli Space of Shapes of a Tetrahedron with Faces of Equal Area

The space of shapes of a tetrahedron with fixed face areas is naturally a symplectic manifold of real dimension two. This symplectic manifold turns out to be a Kahler manifold and can be

parametrized by a single complex coordinate Z given by the cross ratio of four complex numbers obtained by stereographically projecting the unit face normals onto the complex plane.

This Demonstration illustrates how this works in the simplest case of a tetrahedron T whose four face areas are equal. For convenience, the cross-ratio coordinate Z is shifted and rescaled

to z=(2Z-1)/Sqrt[3] so that the regular tetrahedron corresponds to z=i, in which case the upper half-plane is mapped conformally into the unit disc w=(i-z)/(i+z). The equi-area tetrahedron

T is then drawn as a function of the unit disc coordinate w.

Reference: L. Freidel, K. Krasnov, and E. R. Livine, "Holomorphic Factorization for a Quantum Tetrahedron".

Quantum tetrahedron volume, area and angle eigenvalues

by David Horgan.

In this interact I calculate the angle, area and volume for a quantum tetrahedron The angle is found using the expression: theta = arccos((j3*(j3+1)-(j1*(j1+j1)-j2*(j2+1))/(2*sqrt(j1*(j1+j1)*j2*(j2+1)))) The area is found using the expression: A=sqrt(j1*(j1+1)) The volume is fund using the expression V^2 =M = 2/9(real antisymmetrix matrix)

Values of constants gamma is Immirzi parameter gamma =numerical_approx( ln(2)/(pi*sqrt(2))) #G = 6.63*10^-11 hbar= (1.61619926*10^-35)/(2*pi) lp is the planck length lp3=6*10^-104 Reference: Bohr-Sommerfeld Quantization of Space by Eugenio Bianchi and Hal M. Haggard. Reference: Shape in an atom of space: exploring quantum geometry phenomenology by Seth A. Major.

Research Blog: http://quantumtetrahedron.wordpress.com

Given the values of J1, J2, J3 and J4 this interact calculates the volume, area and angle eigenvalues of a quantum tetrahedron.

Quantum tetrahedron Area Operator eigenvalues

by David Horgan.

Given the values of J1, J2, J3 and J4 this interact calculates the area eigenvalues of a quantum tetrahedron.

interact/Loop Quantum Gravity (last edited 2019-04-06 16:42:59 by chapoton)