IMHO this is right and wrong. There's no overall gravitational field, but there is an energy density. A gravitational field is a place where the spatial energy-density is not uniform. If you were midway between two stars the spatial energy density is uniform so you don't fall down, but it isn't zero. A gravitational field is a place where light curves and matter falls down, but it doesn't suck space in. Like I said to paddoboy, the waterfall analogy is garbage. It started with Gullstrand-Painleve coordinates, which Einstein dismissed for good reason. We do not live in some Chicken-Little world. Gravity doesn't stop space expanding. Gravitational field energy is positive. See this: "the energy of the gravitational field shall act gravitatively in the same way as any other kind of energy". Space has an energy density. If it's uniform there's no gravitational field. If it isn't, there is. So they say. But when it comes to gravitational redshift, the photon is emitted with less energy. It doesn't lose energy as it ascends. See this: "An atom absorbs or emits light at a frequency which is dependent on the potential of the gravitational field in which it is situated". Negative pressure is tension. Think of the balloon analogy. You can expand a balloon by reducing the tensile strength of the skin. Think bubblegum.