# Questions tagged [point-particles]

The tag has no usage guidance.

202 questions
Filter by
Sorted by
Tagged with
66 views

### Relationship between Lagrangians describing a particle interacting with a scalar field

In Susskind's Particles and Fields lecture, he considered the Lagrangian obtained by considering a particle and the effects of a scalar field $\phi(t, x)$ with coupling constant $g$ on the particle (...
1 vote
60 views

### Additional electric field due to changing magnetic field around a moving charge

Imagine a point charge moving along x-axis in empty space at a constant velocity $v$. Since the charge is moving, the electric and magnetic field around it should be surmisable from this image (...
• 179
55 views

### Constraint in BRST quantization of point particle

On page 130 of Joe Polchinski's String Theory volume 1 book, the Constraint or the missing equation of motion for point particle after gauge fixing is $H = 0$, and the BRST operator is the ghost $c$ ...
• 97
1 vote
44 views

134 views

1 vote
59 views

### Extended SUSY and superspace

I am trying to understand how to construct an action using the superspace formalism for $\mathcal N>1$. I have read that this is quite difficult to do, so let's consider a simple example. Suppose I ...
• 1,023
88 views

### Actions for relativistic point-particles of higher spin

To describe the behavior of a relativistic point-particle, we have the standard action $$S=\int d\tau \bigg[\frac{1}{e} \dot X^\mu\dot X_\mu +m^2 e\bigg],$$ where $e$ is the worldline einbein. Then, ...
• 1,023
159 views

### General Relativity at Microscopic Scale

If we consider a particle to be point-like, wouldn't it produce a Schwarzschild spacetime in it's vicinity? What does spacetime look-like in the vicinity of point particles? What experiments have been ...
• 699
653 views

### Why the use of proper time as a parameter to describe the worldline only works for *massive* particle?

In Hobson et al, General Relativity: An Introduction for Physicists (pg. 15), it was said that it is natural to describe the worldline of a massive particle by giving the four coordinates $(t,x,y,z)$...
• 4,011