Recent content by Cedric Chia

From my reading of several quantum optics textbooks and spectroscopy texbooks, the emission and absorption spectrum of an atom or molecule are always given in terms of the time-correlation function, for example the emission spectrum of a two level atom is given by: $$...

The emission spectrum or resonance fluorescence for a quantum dot, atom or defect center are discussed in many quantum optics textbook, for example see "Quantum Optics" by Marlan O. Scully and M. Suhail Zubairy Chapter 10 , "Quantum Optics" by D. F. Walls and Gerard J. Milburn Chapter 10 and...

Thank you! You really made my day! I'm using the Griffiths Textbook but never thought of using vector addition on "curly-r / script-r" $$\text{script r} = \vec{r}-\vec{r'}$$ where $$\text{script r}:=\text{the vector starts at source charges (the sphere) and ends at point z}$$...

Thank you for your help but I'm actually looking for an alternative solution. For example: When finding electric field distance z perpendicular above the mid point of a line segment, we usually parameterize: $$\vec{r}=<-x,0,z>$$ in order to get from any point on the line segment to the point...

Homework statement: Find the electric field a distance z from the center of a spherical shell of radius R that carries a uniform charge density σ. Relevant Equations: Gauss' Law $$\vec{E}=k\int\frac{\sigma}{r^2}\hat{r}da$$ My Attempt: By using the spherical symmetry, it is fairly obvious...

For the following distributions find $$E[2^X]$$ and $$E[2^{-X}]$$ if finite. In each case,clearly state for what values of the parameter the expectation is finite. (a) $$X\sim Geom(p)$$ (b) $$X\sim Pois(\lambda)$$ My attempt: Using LOTUS and $$E[X]=\sum_{k=0}^{\infty}kP(X=k)=\frac{1-p}{p}$$...

I know the current of capacitor and inductor must be parallel but pointing in opposite direction due to the fact they are connected in parallel thus having same voltage (please see attached screenshots). The current of resistor will simply be the sum of these two vectors, but what about its...

For a single electron system, it's binding energy would just be -RZ2/n2 (where R = 13.606(eV) ). But when we're talking about multielectron system, it's binding energy would become -RZeff2/n2 (since there will be shielding effect due to the inner elecrons, where we need to figure out the Zeff...

1) I know that the binding energy is the energy that holds a nucleus together ( which equals to the mass defect E = mc2 ). But what does it mean when we are talking about binding energy of an electron ( eg. binding energy = -Z2R/n2 ? ). Some website saying that " binding energy = - ionization...

thank you very much, you are very helpful

I think that would be (volume I need to observe) / (total sphere volume) = (10000) / (4188790) = 2.39⋅10-3

Thank you for the quick reply, the total volume of the sphere is 4188790 Mpc3 ("which indicates the volume of sky I could possibly observed is 4/3⋅π⋅d3 = 4188790 Mpc3") and the volume I need to view is 10000Mpc3 ("thus V=10000Mpc3, which is the volume I need to observed to find 100...

How can I find solid angle relative to the 10000MPc3?

Homework Statement Given that there are 10-2 Ellipticals per Mpc3 and my garden telescope can reach to 14 mag. How large an area of sky would I need to survey to find 100 Elliptical galaxies ? (assume the typical absolute magnitude for an Elliptical galaxy is -21 mag).Homework Equations...

yess I'm really sorry I've forgot to put another M in the second equation! correction: to find mass occupied by the starts in the range x and y: fM = ∫xy M-7/3 M dM / ∫0.120 M-7/3 M dM