These ideas are of no scientific value, for the following reason: if you consider General Relativity in reverse, as a theory of stress-tensors given a geometry, then any geometry is a solution of Einstein's field equation by simply setting

$$T_{\mu\nu} = 8\pi G_{\mu\nu}$$

For your given metric. In other words, whatever metric you make up, you get a stress tensor which corresponds to this. There is no restriction from General Relativity on the allowed geometry without further energy conditions.

What that means is that if I have any manifold with metric g(x), and a differentiable curve x(t), and I wish to shrink the proper time for traversing that curve to as close to zero as I like, all I have to do is choose a tube perpendicular to the curve, and multiply the metric in the interor by any function of the radial coordinate interpolating from a small value to 1 that I like:

$$ g\rightarrow g*f(r) $$

where r is the radial tube-distance to the curve. As long as the tube is small, and f is constant as a function of the curve proper time, this will look like a relatively fixed "object" traveling along the curve, your "warp engine", which magically reduces the metric on the interior so that the curve can be traversed as quickly as you like. You simply choose f(r) to interpolate from the small number (the inverse warp factor) at 0, where it is completely flat, to 1 at some small radius R, where it is also completely flat. And there you have it, a warp drive!

None of this nonsense construction can be said to be a solution of General Relativity, neither the Alcubierre solution nor the solution in this White paper, because there are *no conditions *from General Relativity without energy conditions. Every geometry works. So it is trivial to construct Warp drives, and if I were in the business I could make up a new "warp drive" every day for all eternity, by choosing a different function f, or making angular dependence, whatever.

The physical content of classical General Relativity requires at least the null energy condition, so that the warp drive does not violate the black hole area law, which is the second law of thermodynamics. All these drives allow you to travel faster than light, and therefore escape a horizon, and so all of them violate the null energy condition. Without this, the weakest condition, there is no content to GR, so there is no content to these claims. They are simply inventions.