Evaluating an 'odd' integral

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In summary, the conversation is about an integral that needs to be evaluated and graphed. It is a line of sight (l.o.s) integral and the equation is used to calculate the prompt emission factor for annihilating dark matter particles in the Milky Way. The individual is seeking help in understanding the calculation and asks for assistance from someone knowledgeable in this topic. They also have specific questions about the topic and are unsure if the integral needs special considerations or if there are angle dependencies. It is clarified that the integral is just a regular, one-dimensional integral and the term "line of sight" simply determines which part of the density is being looked at.
  • #1
majormuss
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Hi all,
I attached a picture of an integral that I need to evaluate and graph. It is a line of sight (l.o.s) integral which I have never come never come across before. The equation is called a prompt emission factor for annihilating dark matter particles for the milky way. Could someone please show me how its done? Also if there's anyone who knows this topic really well (dark matter distribution and annihilation in the milky way) please let me know. I have a few questions that I can't find answers to online. Thanks!
 

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If you have the dark matter density, the integral should be easy to evaluate - square the density, calculate the integral.

Is your question where that formula comes from? Or how to calculate back to the dark matter density if we know the flux observed in all directions?
 
  • #3
Thanks mfb. I was confused about how to evaluate an l.o.s integral. I mean do I evaluate it as a normal integral? or does it need a special consideration since it is l.o.s? I also heard the l.o.s integral have some angle dependencies. Is this right?
 
  • #4
It is just a regular, one-dimensional integral. "Line of sight" just determines which part of the density you look at.
 
  • #5


Hello,

Thank you for sharing your question about evaluating this 'odd' integral. I can understand your curiosity about this equation and its relevance to the topic of dark matter distribution and annihilation in the Milky Way.

To begin, let's break down the integral and understand its components. The integral is a line of sight (l.o.s) integral, which means it involves integrating along a line of sight. In this case, it is the line of sight through the Milky Way. The equation is called a prompt emission factor for annihilating dark matter particles, which suggests that it relates to the amount of energy emitted when dark matter particles annihilate.

To evaluate this integral, we need to understand the function inside the integral, which is the dark matter density profile. This profile describes the distribution of dark matter in the Milky Way. Depending on the model used, this profile can vary, and therefore, the integral will give different results. This is why it is important to use a well-supported model for the dark matter density profile when evaluating this integral.

As for graphing the integral, it would be helpful to plot the function inside the integral as a function of the line of sight, and then integrate over that function to get the total amount of prompt emission. This can be done using numerical methods or by breaking the integral into smaller, more manageable parts.

In terms of finding someone who is knowledgeable about this topic, I suggest reaching out to researchers or experts in the field of dark matter and astrophysics. They would be able to provide you with more detailed explanations and potentially answer your questions.

I hope this helps in your understanding of this 'odd' integral. Keep exploring and asking questions, as that is the essence of science. Good luck!
 

1. What is an 'odd' integral?

An 'odd' integral is an integral in which the integrand function is an odd function. This means that the function has symmetry about the origin, and it satisfies the property f(-x) = -f(x). In terms of the integral, this means that the integral from -a to a will always be equal to 0, where a is any real number.

2. Why is evaluating an 'odd' integral different from a regular integral?

When evaluating a regular integral, the limits of integration can be any real numbers. However, for an 'odd' integral, the limits of integration must always be symmetric about the origin, such as -a and a. This is because the function being integrated has special properties at these points, making the integral easier to evaluate.

3. What are some examples of 'odd' functions?

Examples of 'odd' functions include sine, cosine, and tangent. These functions have symmetry about the origin and satisfy the property f(-x) = -f(x). Other examples include functions such as x^3, x^5, and 1/x, which also have symmetry about the origin.

4. How can I evaluate an 'odd' integral?

To evaluate an 'odd' integral, you can use the property that the integral from -a to a is always equal to 0. This means that you can split the integral into two parts, from 0 to a and from -a to 0, and then solve each part separately. You can also use substitution or integration by parts, if needed.

5. What are some real-world applications of 'odd' integrals?

'Odd' integrals have many real-world applications in physics and engineering. For example, they are used in calculating the center of mass and moment of inertia for objects with symmetry about the origin. They are also used in calculating the work done by a force on an object, as well as in solving differential equations in mechanics and electricity and magnetism.

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