'Should conditionals be emergent ...': asyndetic conditionals in English and German as a Challenge to Grammaticalization Research

The present article examines asyndetic or conjunctionless conditionals in German and English. According to Jespersen’s Model (1940), this construction arose diachronically from a paratactic discourse sequence with a polar interrogative, but more recently Harris and Campbell (1995) have claimed that this model lacks any theoretical and empirical foundation. To demonstrate how asyndetic conditionals may emerge from discourse, this study reframes Jespersen’s Model in grammaticalization terms and adduces several constructional features in order to show that a grammaticalization process has actually taken place. In particular, this is achieved by applying traditional grammaticalization parameters such as bondedness, paradigmatic variability and specialization to synchronic and diachronic variation patterns with regard to clause integration, the finite verb of the protasis and the possible-world categories realis, potentialis, irrealis. The article also explores the relevance of speech-situation evocation to the formation of interrogative-based conditionals

Efficient classical simulations of quantum Fourier transforms and normalizer circuits over Abelian groups

The quantum Fourier transform (QFT) is sometimes said to be the source of various exponential quantum speed-ups. In this paper we introduce a class of quantum circuits which cannot outperform classical computers even though the QFT constitutes an essential component. More precisely, we consider normalizer circuits. A normalizer circuit over a finite Abelian group is any quantum circuit comprising the QFT over the group, gates which compute automorphisms and gates which realize quadratic functions on the group. We prove that all normalizer circuits have polynomial-time classical simulations. The proof uses algorithms for linear diophantine equation solving and the monomial matrix formalism introduced in our earlier work. We subsequently discuss several aspects of normalizer circuits. First we show that our result generalizes the Gottesman-Knill theorem. Furthermore we highlight connections to Shor's factoring algorithm and to the Abelian hidden subgroup problem in general. Finally we prove that quantum factoring cannot be realized as a normalizer circuit owing to its modular exponentiation subroutine.Comment: 23 pages + appendice

The Future of Dams Project: Governance Statement

This governance statement sets out shared principles to guide our work and our relationships with each other on the New England Sustainability Consortium’s Future of Dams project. This is a living document, meant to evolve as our partnership evolves. Rather than offering an exhaustive catalog, this governance statement is meant to serve as a touchstone to prompt important conversations about conduct, conflict resolution, authorship, expectations, data sharing, and assessment

Principal noncommutative torus bundles

In this paper we study continuous bundles of C*-algebras which are non-commutative analogues of principal torus bundles. We show that all such bundles, although in general being very far away from being locally trivial bundles, are at least locally trivial with respect to a suitable bundle version of bivariant K-theory (denoted RKK-theory) due to Kasparov. Using earlier results of Echterhoff and Williams, we shall give a complete classification of principal non-commutative torus bundles up to equivariant Morita equivalence. We then study these bundles as topological fibrations (forgetting the group action) and give necessary and sufficient conditions for any non-commutative principal torus bundle being RKK-equivalent to a commutative one. As an application of our methods we shall also give a K-theoretic characterization of those principal torus-bundles with H-flux, as studied by Mathai and Rosenberg which possess "classical" T-duals.Comment: 33 pages, to appear in the Proceedings of the London Mathematical Societ

Quantum simulation of classical thermal states

We establish a connection between ground states of local quantum Hamiltonians and thermal states of classical spin systems. For any discrete classical statistical mechanical model in any spatial dimension, we find an associated quantum state such that the reduced density operator behaves as the thermal state of the classical system. We show that all these quantum states are unique ground states of a universal 5-body local quantum Hamiltonian acting on a (polynomially enlarged) system of qubits arranged on a 2D lattice. The only free parameters of the quantum Hamiltonian are coupling strengthes of two-body interactions, which allow one to choose the type and dimension of the classical model as well as the interaction strength and temperature.Comment: 4 pages, 1 figur