Kavli Affiliate: Matthew Fisher | Summary:We explore the onset of spontaneous strong-to-weak symmetry breaking (SW-SSB) under U(1)-symmetric (i.e., charge-conserving) open-system dynamics. We define this phenomenon for quantum states and classical probability distributions, and explore it in three complementary models, one of which exhibits nontrivial quantum coherence at short times. Our main conclusions are as follows. […]

Kavli Affiliate: Boris I. Shraiman | Summary:In contrast to inert materials, living cells use molecular motors to generate forces independently of elastic strain. How do local active forces translate into large-scale shape, and what are the mechanical properties of the resulting "living matter"? Here, we address these questions within the active tension network (ATN) model […]

Kavli Affiliate: Boris I. Shraiman | Summary:Connecting cell behavior to tissue shape and mechanics is a fundamental challenge in the physics of morphogenesis. In epithelia, cell-cell interfaces are under internal active tension, and cytoskeletal turnover precludes a fixed "reference shape" that could anchor conventional elastic theory. This "tension-first" setting calls for a different approach. Here, […]

Kavli Affiliate: Boris I. Shraiman | Summary:Connecting cell behavior to tissue shape and mechanics is a key challenge in the physics of morphogenesis. Cytoskeletal turnover precludes a fixed reference state, and tensions are actively generated independently of strain; so conventional elasticity theory is not applicable. Here, we study epithelia governed by quasi-static force balance between […]

Kavli Affiliate: Leon Balents | Summary:We study Gutzwiller-projected wavefunctions for triangular-lattice U(1) Dirac spin liquids in a Zeeman field, where we allow the U(1) gauge field to develop a gauge flux, resulting in (spin-split) spinon Landau levels. We find that at a given magnetization, the optimal candidate state has a finite flux chosen such that […]

Kavli Affiliate: Boris I. Shraiman | Summary:A constitutive relation between stress and strain relative to a reference state is the basic assumption of elasticity theory. However, in living matter, stress is governed by (motor molecule) activity rather than a constitutive law. What paradigm takes the place of elasticity in this setting? Here, we derive a […]

Kavli Affiliate: Boris I. Shraiman | Summary:A constitutive relation between stress and strain relative to a reference state is the basic assumption of elasticity theory. However, in living matter, force generation is governed by motor molecule activity, which does not depend on deformation relative to a reference. A different approach is needed to describe how […]