Gamma Definition and 714 Threads

Hi, my question is that would it be possible to reduce the energy and frequency of gamma rays to visible light then maintain it at that level?

Hi folks Please bear with me, I'm new here and this may not be the correct forum to ask this question. If this is the case, I'll of course remove my question and ask it the appropriate place instead. However, here it goes: I need to be able to calculate how much a given intensity of gamma...

Is there any known limit to the energy of a photon? I've seen a reference to pair production in the highest bracket over 1.02 MeV and I've seen references to energies from cosmic sources in the TeV range which aren't very well understood but is there any theoretical limit?

I'm reading through some lecture notes and there is a proof that the gamma matrices are traceless that I've never seen before (I've seen the "identity 0" on wikipedia proof) and I can't work out some of the steps: \begin{align*} 2\eta_{\mu\nu}Tr(\gamma_\lambda) &=...

Hi, How exactly does one derive ##E = \gamma mc^2##? Is this an expression for "total energy" contained in an object? The velocity of an object differs between frames of reference right? So doesn't that mean that E differs between frames as well? If it varies between frames can it even...

Skin Effect: . where = resistivity of the conductor = angular frequency of current = 2π × frequency = relative magnetic permeability of the conductor = the permeability of free space ------------------------------ From Wiki According to Skin Effect, the higher the frequency, the less...

Interestingly, I seem to have an integral I have posted before, but I want to take a different approach to it. $\int_{0}^{1} \frac{\ln(1+x)}{1+x^2} \,dx$ The beta function states, $B(x,y) = \int_{0}^{1} {t}^{x-1}({1-t}^{y-1}) \,dx$ So, I was just thinking if there a possible way to compute...

Homework Statement Evaluate the integral by closing a contour in the complex plane $$\int_{-\infty}^{\infty} dx e^{iax^2/2}$$ Homework Equations Residue theoremThe Attempt at a Solution My initial choice of contour was a semicircle of radius R and a line segment from -R to R. In the limit R to...

Say we have a one dimensional chain of N mass points separated by springs of spring constant k. This system can be quantized? Let the quantized system above be at rest and let one of the end mass points emit a photon of energy E along the crystal axis. Will we get physics similar to he...

Gammaray bursts (GRB) may affect the prevalence of life in various different regions of the galaxy. http://arxiv.org/abs/1409.2506 On the role of GRBs on life extinction in the Universe Tsvi Piran, Raul Jimenez (Submitted on 8 Sep 2014) As a copious source of gamma-rays, a nearby Galactic...

This is a pretty basic question, but I haven't seen it dealt with in the texts that I have used. In the proof where it is shown that the product of a spinor and its Dirac conjugate is Lorentz invariant, it is assumed that the gamma matrix \gamma^0 is invariant under a Lorentz transformation. I...

Can the above logic be applied to Schw. Metric as well? Suppose I have an object moving with a radial velocity v=const, then can I do the same to derive the Schwarchild time dilation as in the Minkowski? dr = v ~ dt ds^{2} = [K - \frac{v^2}{K} ] dt^2 So \gamma ^{-1} = \sqrt{K} [1 -...

Homework Statement Determine coordinate direction angle γ of the resultant force acting at B. Homework Equations Cos\gamma = F\underline{}z/F The Attempt at a Solution The first part was to find magnitude of F\underline{}b. The next part was finding the other coordinate...

My first question is: is this formula (at the bottom) a known formula? In this subject i haven't explained how i build up the formula. So far i think it is equal to the gamma function of Euler with \Gamma\left(\frac{m_1}{m_2}+1\right)= \frac{m_1}{m_2}\ ! with m_1 , m_2 \in...

I am trying to simplify the expression \not p \gamma^\mu \not p. I believe the answer should be - \frac{1}{2} \gamma^\mu p^2, but I am not sure. Tom

I am reading through Borwein's paper, "Fast evaluation of the gamma function for small rational fractions using complete elliptic integrals of the first kind" and have a question. If we look at his algorithm's we see they are of this general form...

I have heard that the Borwein/Zucker algorithm for computing certain values of the gamma function is pretty awesome, but finding it online is proving elusive... Does anyone know the algorithm?

Hey everyone I'm new here and this is my first thread, although i have great interest in chemistry and physics my knowledge of these fields is very basic( I'm graduated in economics) so don't be surprised if i ask something that may look silly. so here are my firsts questions. -Is it...

Definition/Summary The gamma function denoted by \Gamma (n) is defined by \Gamma (n) = \int_{0}^{\infty} x^{n-1} e^{-x} dx is convergent for real and complex argument except for 0, -1, -2, ...-k Equations Useful identities: \Gamma(n+1)=n! \Gamma (x+1) = x\Gamma(x)...

http://en.wikipedia.org/wiki/Gamma_matrices#Normalization See the image below. Which of us is right: me or Wikipedia?

Hi Board, In the Spectrum of Co60 http://upload.wikimedia.org/wikipedia/commons/thumb/2/24/Co60_Spectrum.JPG/776px-Co60_Spectrum.JPG i see the two peaks of the 4-2-0 Cascade. Looking at a table of Nuclides http://atom.kaeri.re.kr/cgi-bin/decay?Co-60%20B- i found that the peaks...

Hi guys I am looking for a dataset to use in my thesis. I am working on UNION 2.1 sample of supernovea Ia data. That dataset consist of redshift and distance modulus with uncertainty (sigma) for 590 supernovea. Do you guys know where can i find similar dataset for GRBs?

Are there any good textbooks for gamma functions? Explaining them? Because I need to evaluate stuff like ∫e^x^3 dx or ∫sin(x^2) dx

Hi guys, Could someone refer me to sources which explain and give examples for crystals which absorb xray / gamma ray and emit RF ? Meaning that if I radiate a crystal with xray I get RF so I can theoretically track its movement in the enclosed are. Thanks a lot!

Homework Statement An experiment you're designing needs a gas with γ = 1.49. You recall from your physics class that no individual gas has this value, but it occurs to you that you could produce a gas with γ = 1.49 by mixing together a monatomic gas and a diatomic gas. What fraction of the...

Could someone please explain why the following sum simplifies to the following? = As far as I can see, this sum does not correlate to the formula for incomplete gamma function as a sum. I'd appreciate any help as the incomplete gamma function is somewhat beyond the scope of my current...

Homework Statement Let X1, X2,...,Xn be a random sample from the exponential distribution with mean θ and \overline{X} = \sum^{n}_{i = 1}X_i Show that \overline{X} ~ Gamma(n, \frac{n}{θ}) Homework Equations θ = \frac{1}{λ} MGF Exponential Distribution = \frac{λ}{λ - t} MGF Gamma...

So i have a question regarding a homework question I'm working on which suggest a neutral pion traveling with velocity v decays into two gamma rays of equal theta to the normal and they of course have velocity c. It then asks to prove that v= cos theta Which kind of confuses me. I mean if...

Problem: Evaluate: $$\int_0^{\infty} t^{-1/4}e^{-t}\,dt$$ Attempt: I recognised this one as $\Gamma(3/4)$. I found a few formulas on Wolfram Mathworld website which helps to evaluate this but I am wondering if I can solve the definite integral from elementary methods (like by parts). Any help...

I am using a wikipedia page, Derivation of the Lorentz transformations and a lot of historical papers. To follow through I came up with my own transformations that do not contain the gamma factor: ##x^{'}=x-\beta ct## ##t^{'}=t-\beta \frac{x}{c}## When applying them to a waveform...

In Wikipedia it reads that γ(1+β) = \sqrt{\frac{1+β}{1-β}}, however, if I did my homework correctly I get γ(1+β) = \sqrt{\frac{1+β^{2}}{1-β^{2}}}. Digging more deeply into why Wikipedia is listing it as such I found that it is based on the hyperbolic angles:γ=coshΘ. But it leads to definitions...

I was taking a break from studying from my real analysis, electrodynamics, and nuclear physics exams this week, and, being a math-phile, I decided to play around with the gamma-function for some reason. Anyway, I used the common product expansion of the multiplicative inverse, and I arrived at a...

I have a hard time believing we only have the limited number of series I have seen so far especially considering how much broader mathematics is than I had thought just a short while ago. Where should I search to find more infinite series summations for the gamma function? For example which...

Does anyone know if we currently have an infinite series summation general solution for the gamma function such as, $$\frac{1}{\Gamma(k)}=\sum_{n=0}^{\infty} f(n,k)$$ or, $${\Gamma(k)}=\sum_{n=0}^{\infty} f(n,k)$$?

I'm currently doing a spectroscopy lab where you use a scintillator and Cs-137 to obtain a Cs-137 spectrum. I calibrated this spectrum using the known gamma energy for Cs-137 at 662 Kev at the photo peak. I am now trying to use this calibration for a Co-60 spectrum. The problem is that when I...

Hi, It has been a long time since I have worked with pdfs so perhaps someone can help. According to Wikipedia (http://en.wikipedia.org/w/index.php?title=Chi-squared_distribution#Additivity) the pdf of the addition of n independend Chi_squared distributed R.V.s is also Chi_squared distributed...

I'm not sure if this is a "general" math question but I do think it is an interesting one. The Gamma Function, \Gamma(t), has many interesting definitions. It can take on the form of an integral to an infinite product. There is one particular definition, however, that I am trying to...

I am given that The kth moment of an exponential random variable with mean mu is E[Y^k] = k!*mu^k for nonnegative integer k. I found m^2 (0) = (-a)(-a-1)(-beta)^2. The answer I found is however mu^2+a*beta^2 which is different from the k! From the given formula. Could someone help me figure it...

I recently read the following article: It was not very long, and it did not contain much information. However, after a little searching I discovered the article was referring to GRB 130427A. The key features of this GRB are its strength at 94 GeV, and its duration at "better part of a...

Hi, In QFT we define the projection operators: \begin{equation} P_{\pm} = \frac{1}{2} ( 1 \pm \gamma^5) \end{equation} and define the left- and right-handed parts of the Dirac spinor as: \begin{align} \psi_R & = P_+ \psi \\ \psi_L & = P_- \psi \end{align} I was wondering if the left- and...

Dear PhysicsForum, We have just treated the Dirac equation and its lagrangian during our QFT course, but we have only gone in depth in 3+1 dimensions. My question is about what happens to spin in 2+1 dimensions. In 3+1 dimensions we have to use 4 by 4 gamma matrices, but in 2+1 dimensions we...

Really quick question. In a graph like this: http://en.wikipedia.org/wiki/File:Cs137_Spectrum.PNG Source What does the Channel Number represent? Also, just to make sure, am I right in saying the count rate is \frac{\delta m}{\delta t} ? where m is the cumulative number of scintillations and...

http://img202.imageshack.us/img202/3224/620u.jpg In A for this question F(alpha+1)=alpha*F(alpha) and I'm curious as to how the RHS of this still has the gamma function in it?

Homework Statement I have that X is distributed with Gamma(a,b) and that Y = \frac{1}{X}. I found the pdf of Y to be \frac{1}{\Gamma(a)b^a} \left(\frac{1}{y}\right)^{a+1} e^{-1/yb} for y > 0. I need to use this to find the expected value. Homework Equations The gamma function is...

Homework Statement Question wants you to a) find the difference between Egamma and the excitation energy of the nucleus due to the fact that the nucleus recoils. (using approximation that Egamma is small relative to nucleus mass. other parts are simple if I can get a)Homework Equations...

Homework Statement Prove that \gamma^{a}\gamma^{b}\gamma^{c}\gamma^{d}\gamma^{e}\gamma_{a} = 2\left(\gamma^{e}\gamma^{b}\gamma^{c}\gamma^{d}+\gamma^{d}\gamma^{c} \gamma^{b}\gamma^{e}\right) Each of the \gamma^{i}s are as used in the Dirac equation. Homework Equations...

Homework Statement "Show that - \int^1_0 x^k\ln{x}\,dx = \frac{1}{(k+1)^2} ; k > -1. Hint: rewrite as a gamma function. Homework Equations Well, I know that \Gamma \left( x \right) = \int\limits_0^\infty {t^{x - 1} e^{ - t} dt}. The Attempt at a Solution I've tried various substitutions...

99% of all marine fossil generating species on Earth that ever existed have gone extinct. There are periods in the fossil record that show massive extinction rates. For example, the K-T (now the K-Pg) boundary marks the extinction of dinosaurs in the fossil record along with marine animals, at...

Hi, My understanding of shaping time on amplifiers is that its the amount of time the capacitor has to collect charge. I would say that the longer the time the better energy resolution you would have due to that all the charge created from the photon is collected. However, if the time is long...

Hi, I was doing a measurement on a Cs-137 source, strong enough so that my detector registers a sum peak. I can't get my head around A, the peak at ~80 keV.. I get B (backscatter peak), C(compton edge) and D total abs.peak. I tried with a weaker Cs-137 and I saw the 35keV (Ba) but no...