Talk given at Oxford Philosophy of Physics, LSE's Sigma Club, the Munich Center for Mathematical Philosophy, Carlo Rovelli's 60th birthday conference.
I construe dualities in physics as particular cases of theoretical equivalence. The question then naturally arises whether duality is compatible with emergence. For the the focus of emergence is on novelty rather than on equivalence.
In the first part of the talk, I review recent work dealing with this question. I exhibit two ways in which duality and equivalence can be made compatible, and I give an example of emergence in gauge/gravity dualities: dualities between a theory of gravity in (d+1) dimensions and a quantum field theory (QFT) in d dimensions.
In the second part of the talk, I present new results on the question whether diffeomorphisms in gravity theories emerge from QFTs. I critically assess the following idea, taken from the physics literature: given that (a) the QFT is not a diffeomorphism invariant theory, and that (b) there is a duality between the QFT and the gravity theory, are we entitled to (c) conclude that the diffeomorphisms of the gravity theory emerge from the QFT?
I argue that one must distinguish different kinds of diffeomorphisms: some diffeomorphisms are ‘invisible’ to the QFT: all of the QFT’s quantities are invariant under them, therefore the QFT does not ‘see’ them. But other diffeomorphisms are ‘visible’ to the QFT. The invisible diffeomorphisms prompt a ‘Bulk Argument’, in analogy with the Hole Argument. The analysis of emergence is different for these different kinds of diffeomorphisms, and I discuss the way in which we can speak of emergence of diffeomorphisms in gauge/gravity dualities.
Talk given in London, 3 January 2017. The talk has three aims:
(i) To clarify the use of these concepts (‘emergence’ and ‘reduction’) in science, especially in physics.
(ii) Specifically: to argue that the contrast ‘emergence vs. reduction’ poses a false dichotomy, since these two concepts are independent.
(iii) To point out that the independence of the two concepts may open interesting avenues for the philosophy of mind. But I will not work this out in a theory of the mind.
Talk given at Oxford Philosophy of Physics, LSE's Sigma Club, the Munich Center for Mathematical Philosophy, Carlo Rovelli's 60th birthday conference.
I construe dualities in physics as particular cases of theoretical equivalence. The question then naturally arises whether duality is compatible with emergence. For the the focus of emergence is on novelty rather than on equivalence.
In the first part of the talk, I review recent work dealing with this question. I exhibit two ways in which duality and equivalence can be made compatible, and I give an example of emergence in gauge/gravity dualities: dualities between a theory of gravity in (d+1) dimensions and a quantum field theory (QFT) in d dimensions.
In the second part of the talk, I present new results on the question whether diffeomorphisms in gravity theories emerge from QFTs. I critically assess the following idea, taken from the physics literature: given that (a) the QFT is not a diffeomorphism invariant theory, and that (b) there is a duality between the QFT and the gravity theory, are we entitled to (c) conclude that the diffeomorphisms of the gravity theory emerge from the QFT?
I argue that one must distinguish different kinds of diffeomorphisms: some diffeomorphisms are ‘invisible’ to the QFT: all of the QFT’s quantities are invariant under them, therefore the QFT does not ‘see’ them. But other diffeomorphisms are ‘visible’ to the QFT. The invisible diffeomorphisms prompt a ‘Bulk Argument’, in analogy with the Hole Argument. The analysis of emergence is different for these different kinds of diffeomorphisms, and I discuss the way in which we can speak of emergence of diffeomorphisms in gauge/gravity dualities.
Talk given in London, 3 January 2017. The talk has three aims:
(i) To clarify the use of these concepts (‘emergence’ and ‘reduction’) in science, especially in physics.
(ii) Specifically: to argue that the contrast ‘emergence vs. reduction’ poses a false dichotomy, since these two concepts are independent.
(iii) To point out that the independence of the two concepts may open interesting avenues for the philosophy of mind. But I will not work this out in a theory of the mind.