What is the Concept of a Fractional Dimension Probability Sphere?

bchui
Messages
41
Reaction score
0
I have heard of such idea:

A sphere of fractional dimension 0<s<1 is understood as a probability sphere with probability s to have an electron at a certain position

for example the volume of the sphere S^{n-1} in \Re^n has volume

Vol(S^{n-1})= (2\Pi^{n/2})/(\Gamma(n/2)

and we can apply the result to non-integer values of n

Anyone have heard of this idea and show me the link for further information? :confused:
 
Physics news on Phys.org
I have been searching for the same thing, and a few places say that it is given by:

\Gamma^2(1/2)/\Gamma(n/2)

for any dimension, even fractional ones, but I am trying to find a way to prove it myself, perhaps using integration with respect to the Hausdorff measure (since it recognizes non-integer dimensions). And just a note- the formula you gave is actually the area measure of the unit S^{n-1} sphere, the volume of the unit S^{n-1} sphere is actually:

Vol(S^{n-1})=[2\pi^{(n-1)/2}]/[\Gamma((n-1)/2+1)],

**Note that the denominator can be rewritten {(n-1)/2}\Gamma((n-1)/2)}.
 
The proof for integer n is simple and done by induction. It could be found for example in

Chapter 5.9 of W Fleming: "Functions of Several Variables", Springer-
Verlag 1977

We generalize n! to \Gamma(n+1) and the formula is obtained.
My problem is the physical aspect. What is the physical mean of a "fractional sphere" and could it possibly be related to "probability sphere" in Quantum Mechanics?
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
I am reading WHAT IS A QUANTUM FIELD THEORY?" A First Introduction for Mathematicians. The author states (2.4 Finite versus Continuous Models) that the use of continuity causes the infinities in QFT: 'Mathematicians are trained to think of physical space as R3. But our continuous model of physical space as R3 is of course an idealization, both at the scale of the very large and at the scale of the very small. This idealization has proved to be very powerful, but in the case of Quantum...
Thread 'Lesser Green's function'
The lesser Green's function is defined as: $$G^{<}(t,t')=i\langle C_{\nu}^{\dagger}(t')C_{\nu}(t)\rangle=i\bra{n}C_{\nu}^{\dagger}(t')C_{\nu}(t)\ket{n}$$ where ##\ket{n}## is the many particle ground state. $$G^{<}(t,t')=i\bra{n}e^{iHt'}C_{\nu}^{\dagger}(0)e^{-iHt'}e^{iHt}C_{\nu}(0)e^{-iHt}\ket{n}$$ First consider the case t <t' Define, $$\ket{\alpha}=e^{-iH(t'-t)}C_{\nu}(0)e^{-iHt}\ket{n}$$ $$\ket{\beta}=C_{\nu}(0)e^{-iHt'}\ket{n}$$ $$G^{<}(t,t')=i\bra{\beta}\ket{\alpha}$$ ##\ket{\alpha}##...
Back
Top