Let me begin by saying that I’ve only glanced the companion paper very briefly and, although I have noticed the paragraph you quote, I may be unaware of other parts that directly address my response.
My remark that the approach wouldn’t work in a Stern-Gerlach experiment was aimed at the three steps structure of the experiment, not at the decoherence happening. If we consider the Stern-Gerlach apparatus as the observer, sure it decoheres, but there’s no middle environment upon which to distribute the measure of the system observed.
To make Carroll-Sebens procedure to work, you need both a three steps experiment and a wide middle enviroment, so it won’t work in any case where one of the element is missing.
Let me begin by saying that I’ve only glanced the companion paper very briefly and, although I have noticed the paragraph you quote, I may be unaware of other parts that directly address my response.
My remark that the approach wouldn’t work in a Stern-Gerlach experiment was aimed at the three steps structure of the experiment, not at the decoherence happening. If we consider the Stern-Gerlach apparatus as the observer, sure it decoheres, but there’s no middle environment upon which to distribute the measure of the system observed.
To make Carroll-Sebens procedure to work, you need both a three steps experiment and a wide middle enviroment, so it won’t work in any case where one of the element is missing.