1,943 research outputs found
What Does '(Non)-Absoluteness of Observed Events' Mean?
Recently there have emerged an assortment of theorems relating to the
'absoluteness of emerged events,' and these results have sometimes been used to
argue that quantum mechanics may involve some kind of metaphysically radical
non-absoluteness, such as relationalism or perspectivalism. However, in our
view a close examination of these theorems fails to convincingly support such
possibilities. In this paper we argue that the Wigner's friend paradox, the
theorem of Bong et al and the theorem of Lawrence et al are all best understood
as demonstrating that if quantum mechanics is universal, and if certain
auxiliary assumptions hold, then the world inevitably includes various forms of
'disaccord,' but this need not be interpreted in a metaphysically radical way;
meanwhile, the theorem of Ormrod and Barrett is best understood either as an
argument for an interpretation allowing multiple outcomes per observer, such as
the Everett approach, or as a proof that quantum mechanics cannot be universal
in the sense relevant for this theorem. We also argue that these theorems taken
together suggest interesting possibilities for a different kind of relational
approach in which dynamical states are relativized whilst observed events are
absolute, and we show that although something like 'retrocausality' might be
needed to make such an approach work, this would be a very special kind of
retrocausality which would evade a number of common objections against
retrocausality. We conclude that the non-absoluteness theorems may have a
significant role to play in helping converge towards an acceptable solution to
the measurement problem.Comment: Corrected comments about whether Lawrence et al theorem requires a
Locality assumptio
Absoluteness via Resurrection
The resurrection axioms are forcing axioms introduced recently by Hamkins and
Johnstone, developing on ideas of Chalons and Velickovi\'c. We introduce a
stronger form of resurrection axioms (the \emph{iterated} resurrection axioms
for a class of forcings and a given
ordinal ), and show that implies generic
absoluteness for the first-order theory of with respect to
forcings in preserving the axiom, where is a
cardinal which depends on ( if is any
among the classes of countably closed, proper, semiproper, stationary set
preserving forcings).
We also prove that the consistency strength of these axioms is below that of
a Mahlo cardinal for most forcing classes, and below that of a stationary limit
of supercompact cardinals for the class of stationary set preserving posets.
Moreover we outline that simultaneous generic absoluteness for
with respect to and for with respect to
with is in principle
possible, and we present several natural models of the Morse Kelley set theory
where this phenomenon occurs (even for all simultaneously). Finally,
we compare the iterated resurrection axioms (and the generic absoluteness
results we can draw from them) with a variety of other forcing axioms, and also
with the generic absoluteness results by Woodin and the second author.Comment: 34 page
- …