1.2 Relativistic Kinematics

Question 1

What do we mean by Lorentz invariance?

Answer 1

Any calculation has the same value in every reference frame

Question 2

What are the four vectors?

Answer 2

X^µ = (t,x,y,z)

Question 3

What is the Einstein summation convention?

Answer 3

Sum over the repeated indices

Question 4

In notation, which 4 vectors are covariant, and which ones are contravariant?

Answer 4

Covariant - subscript

Contravariant - Superscript

Question 5

What is the Minkowski metric matrix?

Answer 5

An operator which converts a covariant matrix to a contravariant matrix

Question 6

State the form of the covariant and contravariant 4 vectors

Answer 6

Covariant - X_µ = (t, -x, -y, -z)

Contravariant - X^µ = (t,x,y,z)

Question 7

What is the 4 vector form for momentum?

Answer 7

p^µ = (E, p)
Has the particle energy as its time like component
- 3 momentum particle vector as its spatial component

Question 8

What is the square of the 4 momentum vector equal to?

Answer 8

The mass of the particle squared