# Tag Info

## New answers tagged symmetry

• 202k

### Why $n-1$ point function vanishes in $D=0$ scalar theory?

In the absence of space-time coordinates ($D=0$), the functional integral of the (Euclidean) "field" theory with the Lagrangian $g \phi^n$ reduces to an ordinary integral and the generating ...
• 5,938

### What is the real shape of Earth?

Yes, Earth does take the shape of an oblate spheroid, but only to a very marginal extent, such that it is barely noticeable. If you are looking for a planet that more obviously takes the shape of an ...
• 194
1 vote

### What is the real shape of Earth?

The shape of the earth is called the geoid. An ellipsoid is just an approximation, and the geoid deviates from the reference ellipsoid by up to 106 m. A sphere is, in turn, an approximation to the ...
• 100k
1 vote

### What is the real shape of Earth?

Well the truth is that NASA doesn't have pictures of around Earth. However, your point is well taken in that the pictures certainly look like they show a round Earth. Even though the Earth is indeed ...
• 4,053
1 vote

### What is the real shape of Earth?

An oblate spheroid does not need to be very oblate to qualify as oblate. This one is not. It's that simple. The shape of the Earth is, of course, considerably more complex than any idealized shape, ...
1 vote

### $\mathbf F'=\mathbf F$ in special relativity

The covariant Minkowski force can be written in terms of the three-vector force as $${\cal F}^\mu=\left[\gamma\frac{dW}{dt},\gamma{\bf F}\right],$$ where $\bf F$ is three-...
• 1,748
1 vote

### Phase transitions in the XXZ model

For the second question, what should be the case is the moment you get to $T>0$, the "quantum-classical correspondence" with $d+1$ dimension breaks down, and it becomes simply like a $d$ ...
• 321
There is a spherically symmetric Einstein vacuum solution for flat circular velocities. Its line element is the general spherically symmetric line element [1][2] \mathrm{d}s^2=\left(\frac{r_S}{C}-1 \...