What is Gamma: Definition and 711 Discussions

Gamma (uppercase Γ, lowercase γ; Greek: γάμμα gámma) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop /ɡ/. In Modern Greek, this letter represents either a voiced velar fricative or a voiced palatal fricative.
In the International Phonetic Alphabet and other modern Latin-alphabet based phonetic notations, it represents the voiced velar fricative.

View More On Wikipedia.org
Recent contents Top users
  1. M

    Gamma function (infinite product representation)

    I have come across this expression in some notes \Gamma (z) = \frac{1}{z} \prod \frac{(1+ \frac{1}{n})^{z}}{1+ \frac{z}{n}} Do you think it's accurate? I have some doubts because I have looked for it on wokipedia, and I couldn't find it.
  2. J

    Calculating Gamma Ratio: Tricks for Hard Problems

    Hi, I need to calculate \Gamma(7/3)/\Gamma(1/3) is there some trick to doing this type of problem? I'm finding it really hard to do from first principles. Any help would be great, thanks!
  3. FeDeX_LaTeX

    Gamma radioactive decay of anti-particles

    Hello; Just needed to clarify something. When anti-particles undergo gamma radioactive decay, is a gamma ray produced, or an anti-gamma ray? Or something completely different? Thanks.
  4. D

    Unbiased estimator/MSE from a Gamma dist.

    I have given some serious effort to working out and understanding the MLE of a distribution. From the distribution f(x;\theta)= x^{3}e^{-x/\theta}/(6\theta^{4}), I have gotten the MLE theta-hat = xbar/4 I have a lot of difficulty figuring out if it is an unbiased estimator or not. How do I...
  5. R

    Gamma Ray Alternative for Solar Eclipse Study of Relativity

    Validation of relativity has been tested by measuring the apparent position of stars as our view passes by the edge of the sun. A difficulty being that we can not easily view stars with the sun so bright so we wait for an eclipse. I have a few questions: 1) Is this still a difficulty...
  6. Q

    Gamma ray spectroscopy: Germanium detector efficiency calibration.

    Hi all, Got a bit of a problem with a lab experiment at uni (I'm not sure if this is the right place to post this, mods feel free to move it if necessary!) Anyway: We're trying to get a plot of efficiency against energy for a planar germanium detector. We've got spectra for different...
  7. I

    Help With Gamma Function Homework

    Homework Statement I (2n,m) = Integral cos^(2n)O sin^(m)O cosO dO limits are 0 to 2pi and O = theta 0.4/3 = 0.1333 show that I 2n,m = 2n/ m+1 (I2n-2, m+2) Homework Equations I really have no idea how to work with this problem. It is under Gamma function of the instructors...
  8. L

    Gamma spectrum Na-22: Peak origins

    Hey, For my first post here, I had a question about the gamma spectrum of Na-22. I measured the gamma spectrum of Na-22 with a Ge-spectrometer. Using Genie-2000 software I saw two peaks in the spectrum, 1274 keV (peaksurface 3981±1,74%) and 511 keV (peaksurface 25494±0,68%). (Horizontal...
  9. V

    Notation relating to gamma matrices

    Hi My QFT course assumes the following notation for gamma matrices: \gamma ^{\mu_1 \mu_2 \mu_3 \mu_4} = {\gamma ^ {[\mu_1}}{\gamma ^ {\mu_2}}{\gamma ^ {\mu_3}}{\gamma ^ {\mu_4 ]}} what does the thing on the right hand side actually mean? Its seems to be a commutator of some sort.
  10. N

    Scenario of gamma ray bursts if it were to come into contact with the earth's ozone

    Is there a video of that kind of scenario floating around youtube? Have not had any luck finding a video of such a scenario.
  11. S

    Frame-Jumping & Incorrect Gamma Derivations Aplenty

    HI, I've been mulling over the derivation of the Lorentz factor gamma in my head for some time now & had worried about it a bit. I've now discovered that what was bothering me was something called "frame-jumping". This is where you use the Pythagorean Theorem to derive Gamma. If you're...
  12. O

    Gamma ray Energy Spectrum of Cd-109 and Sn-113

    Hi, For my experiment, i need the gamma ray energy spectrum of Cd-109 and Sn-113 with NaI detector. would anyone help me please? thanks everyone.
  13. D

    WR104 Gamma Ray Burst: Fact or Fiction?

    Sorry if I sound crazy, but I just heard about this and would like a reliable fact check before I worry. So I recently heard about this binary star system known as WR104. I read that it was pointed right at us and, at some point in the future, it will release a gamma ray burst that will wipe...
  14. I

    Dimension of the gamma matrices in general dimension

    Dear guys, I read a derivation of the dimension of gamma matrices in a d dimension space, which I don't quite understand. First of all, in d dimension, where d is even. One assumes the dimension of gamma matrices which satisfy \{ \gamma^\mu , \gamma^\nu \} = 2\eta^{\mu\nu}...
  15. N

    Alpha, Beta, Gamma , neutron ray, which one is harmful?

    Homework Statement If you were given 4 cookies, each emitter different ray 1)Alpha, 2)Beta,3) Gamma , 4)neutron You have to make decision of the following: a)eat one of the cookies b)dispose one of the cookies at storage facility called WHIP c)put one of the cookies in your pocket...
  16. C

    Difficult integral (product of gamma func with exp)

    Homework Statement Solve. \int\limits_{0}^\infty \exp\left\{\frac{-2n}{x} - \frac{x}{\theta}\right\} x^{n-1} dx n,\theta are constants. Homework Equations The Attempt at a Solution So actually this problem is from the realm of stats...find the MVUE of P(X<2) where X_i\sim...
  17. R

    Point source (radioactive)that emits 100 gamma per second

    Hi all, i have a critical question. You have a point source (radioactive)..that emits 100 gamma per second. Now if you place a metal or foil (e.g., Al)..will the no. of gamma reduces? If it reduces how to calculate..based on beer law..(if we know the attenuation coefficient of that metal and...
  18. M

    Solving for k With Gamma Function

    k*Γ((n-1)/2 + 1)=Γ(n/2 + 1) I need to solve for k, and I'm having some difficulty manipulating the gamma function to obtain my desired result. Any properties, hints or help would be greatly appreciated.
  19. Y

    Please help in Gamma function to series conversion.

    Can you show me how to get the series representation of \Gamma(n-3/2+1)? For example \Gamma(n+3/2+1)=\frac{(2n+3)(2n+1)!}{2^{2n+2}.n!}. I cannot figure out how to write a series with: n=0 => \Gamma(0-3/2+1)= -2\sqrt{\pi} n=1 => \Gamma(1-3/2+1)= \sqrt{\pi} n=2 =>...
  20. J

    Finding the distance of a gamma ray travels in lead

    Homework Statement The ‘half-thickness’ tells us the thickness of a given material needed to absorb half the incident photons from a particular source. Find the average distance of a gamma ray in lead before its first collision. I have a value for the half thickness (and equivalent half...
  21. Hepth

    D* -> D + gamma BR calculation

    Can anyone walk me through this calculation? I'm not completely sure how to do it (merely a student). So is this considered a 1 body radiative decay? So the factorized amplitude would be something like M \propto <D^0|\bar{u}\gamma_\mu\left(1-\gamma_5\right)c|0>[A_1...
  22. K

    Is the ionising power of alpha particles greater than that of gamma

    I request for help in understanding the following: Q1. Why is the ionising power of alpha particles greater than that of gamma rays? Q2. Why does the ratio of neutrons to protons in a nucleus increase after the emission of an alpha particle? I would like to have a quantitative...
  23. C

    Exploring the Gamma Function: f(3), f(4) and f(5)

    Homework Statement Define the function: f(x)= The integral from 0 to infinity of t^(x)e^(-t)dt. Find f(3), f(4) and f(5). Notice anything? Homework Equations N/A The Attempt at a Solution I assume that I start by finding the integral of f(x). I used wolfram alpha and found that...
  24. N

    Solve Gamma Ray Scattering from 198Au Incident on Al Slab

    Homework Statement A gamma ray from 198Au incident normally on a thick aluminum slab travels 1.45 cm before it undergoes a Compton scattering. Calculate the range of angles through which the gamma could scatter and still have at least a 10% probability of re-emerging from the incident slab...
  25. Q

    Exploring Fusion Reactions in Stars: Proton + Deuteron to 3He + Gamma Ray

    Homework Statement One of the thermonuclear or fusion reactions that takes place inside a star such as our Sun is the production of helium-3 (3He, with two protons and one neutron) and a gamma ray (high-energy photon, denoted by the lowercase Greek letter gamma, ) in a collision between a...
  26. C

    Supernova's Gamma Rays and Comets

    Hi guys, me again, with two questions. Just saw a documentation about supernova, when supernova happens, a huge amount of gamma ray is emitted since it is vacuum in space, why wouldn't the gamma ray hit us? Even if its far and takes a few thousand years for it to reach us, it would eventually...
  27. V

    Dirac Gamma Matricies and Angular Momentum Commutation Relations

    Homework Statement This isn't really the problem, but figuring this out will probably help me with the rest of the problem. I want to know what [\gamma^0, L_x] is. Homework Equations I know the commutation (or rather anticommutation) relations between the gamma matricies, and I know the...
  28. T

    Trying to comprehend the explosive power of a gamma ray burst?

    I'm not sure if this thread fits into this particular forum, but about how many megatons would be equal to the explosive power of a gamma ray burst?
  29. M

    Radiation Emission Spectrums for Alpha, Beta, and Gamma

    Homework Statement I'm taking a nuclear physics seminar, and I'm wondering what causes the differences in the energy spectra between alpha, beta, and gamma emissions. Specifically, why is dispersion for energy values in alpha radiation so different from that of beta? I'm also looking for a...
  30. C

    Integration involving Gamma Distribution

    Homework Statement Evaluate \int^{\infty}_0 \frac{1}{B^{\alpha} \Gamma(\alpha)} \theta^{\alpha + x -1}e^{- \theta(1+B)/B} d \theta Homework Equations The Attempt at a Solution \int^{\infty}_0 \frac{1}{B^{\alpha} \Gamma(\alpha)} \theta^{\alpha + x -1}e^{- \theta(1+B)/B}d...
  31. 1

    Gamma Ray Speed: How Fast Do They Travel?

    Does anyone know the speed that gamma rays travel, as a speed or in proportion to the speed of light. Thanks
  32. R

    Protecting Self from Gamma Source: Find Lead Thickness

    Hello all, i need one suggestion for shielding of a gamma source. I have a gamma source with initial activity of 50 mCi=1.85X10^9Bq. What thickness of lead needed to protect myself! I used the formula I(x)=I exp(-kx). I=50mCi; k=37.6 cm^2/g (linear attenuation for 122 keV) and x the thickness...
  33. N

    Mathematica Plotting Gamma Function: \[Gamma][v]

    \[Gamma][v_] := 1/Sqrt[1 - (v)^2] plot1 = Plot[\[Gamma][v], {v, -.99, .99}, PlotStyle -> {Thick, RGBColor[0.6, 0, 0]}, PlotRange -> All] \.08 plot2 = Plot[0, {v, -.99, .99}, PlotRange -> All] \.08 Show[plot1, plot2, PlotRange -> All, AxesLabel -> {"\!\(\*FractionBox[\"v\"...
  34. Z

    Compton Edge and Gamma Spectroscopy

    Hi, I have measured some spectrums from various gamma sources and I was wondering what kind of fitting I should do to determine the Compton edge. I have access to Logger Pro, Excel, and mathematica. I have fit the photopeak with a Gaussian so I know the uncertainty in the Compton edge, I...
  35. G

    Work out the variance of the gamma

    Hi, I'm trying to work out the variance of the gamma(I'm up the the part where you multiply x^2 by the function), but i don't know how to work out what \gamma(\alpha + 2) equals to i know I am supposed to use the fact that \gamma(\alpha + 1) = \alpha \gamma(\alpha) but i don't...
  36. R

    Exploring Breit-Wigner Profile for Gamma Rays

    Hello PF members, I curious to know some basic idea..why the line shape of nuclear decay is displayed as a Breit-Wigner (BW) profile (x-axis as energy and y-axis as intensity) ??.. or any \gamma ray is often shown as a BW profile?? thanks for your reply.
  37. U

    Derivative of the Gamma Function

    A very vague question: What is the derivative of the gamma function? Here's what I've got, using differentiation under the integral. Can anybody tell me if I'm on the right track? What does my answer mean? \Gamma(z) = \int_0^{\infty} t^{z - 1} \: e^{-t} \; dt The integrand can be...
  38. C

    Proving Inverse Gamma Variance: Step-by-Step Guide

    Hi! Can someone help me prove that the variance for the inverse gamma is: \frac{\beta^2}{(\alpha - 1)^2 (\alpha -2)} I started with: E(x) = \int_0^\infty x \frac{\beta^{\alpha}}{\gamma(\alpha)}(\frac{1}{x})^{\alpha + 1} exp (\frac{-\beta}{x}) dx then i let y = \frac{\beta}{x}; dy =...
  39. parazit

    Create a home made muon or gamma ray detector?

    Hi.I wonder is it possible to create a home made muon or gamma ray detector? And if it is possible would you mind to show me some way? Thanks...
  40. P

    Gamma Function Complex Argument: Problems in Stat Phys & How to Calculate

    \Gamma(z)=\int^{\infty}_0x^{z-1}e^{-x}dz z\in\mathhad{C} In which problems in statistical physics we need gamma functions of complex argument? I don't know how to calculate \Gamma(i) for exaple?
  41. E

    Defining the Gamma Function at z=0

    Hello all, Is there any way to make the Gamma function \Gamma[z] defined at z=0? Because in my calculations, I have a single case among many other cases where the argument of the gamma function equals zero. Regards
  42. L

    What are the two definitions of gamma function and how are they related?

    I spend some time studying special functions recently. I found two definitions of gamma function, one in form of integral and the other in form of infinite products, and I cannot prove of their equivalence. I found the definition in infinite product form important in proofing many properties of...
  43. R

    Can the Gamma Function Summation Be Simplified for 0<Re(s)<1?

    I need to find a way to sum/ a closed form representation for: \sum^{N}_{n=1}\frac{\Gamma(n-s)}{\Gamma(n+s)} 0<Re(s)<1 Thanks for the help in advance.
  44. V

    Is Gamma Ray Emission from a Black Hole Really Possible?

    I just can't comprehend that gamma ray can come out of a black hole. Gamma rays are electromagnetism which contain photons, but photons have no mass. And we all know that a black hole swoops up light as well. And what recaton has the gamma ray on the mass around the black hole? I know It's true...
  45. R

    Incomplete gamma function question

    I need to show whether or not: |\gamma(s,1)| converges for 0<Re(s)<1. Does anyone know of an expansion for this that would prove convergence?
  46. R

    Hypernova release two huge jets of gamma rays

    I know that a Hypernova release two huge jets of gamma rays, but I'm not real sure on how they are formed. Also it was mentioned that by following the burst of gamma rays, we're looking back in time. How is this actually possible. I have a shaky grasp on the idea.
  47. G

    Intergration of imcomplete gamma distribution

    Homework Statement How can i determine the integration of incomplete gamma function. I mean how to determine int_0^1 gammainc(3/4,r). where gammainc(a,x)=int_0^x t^(a-1)e^(-t) dt Homework Equations The Attempt at a Solution
  48. D

    Finding energy of gamma ray with spectoscopy

    Hey everyone, I need to be able to be able to explain how a gamma spectrometer (NaI scintillator) can determine the energy of a given gamma ray (or more particularly, determines the effective dose rate, but that shouldn't be to hard once I figure out how to get the energy). The problem, as far...
  49. D

    What is frequency of a gamma ray emitted from a supernova

    From what i have read the gamma ray frequency cap ranges from 3×10^19 to 3×10^24. I want to know what you guys have heard it is. Are the highest measured gamma ray from a supernova calculated with any time dialated effects? Also what is the thoertical cap of something higher than a gamma ray...
  50. E

    Emission of Gamma and Beta rays : Experimental Problem

    Hi there! The experiment: I'm counting Gamma and beta rays emitted from gamma and beta cylindrical sources, for counting I'm using a simple GM counter, which has nearly the same cylindrical shape (i mean diameter). As we all know this are electromagnetic emissions, so they distance must...
Back
Top