A problematic zygopleuroid gastropod Acanthostrophia revisited

SEM examination of the type series of Acathostrophia acanthica CONTI & FISCHER, 1984 from Middle Jurassic of Italy has shown that this gastropod most likely belongs to the family Protorculidae as previously suggested by NÜTZEL (1998). It is also similar to some Jurassic species of Polygyrinidae, which might also be related to Protorculidae. The supposition of KAIM et al. (2008) that Acanthostrophia is an early member of Abyssochrysidae could not be confirmed

Squeezing in a nonlocal photon fluid

Quantum fluids of light are an emerging tool employed in quantum many-body physics. Their amazing properties and versatility allow using them in a wide variety of fields including gravitation, quantum information and simulation. However the implications of the quantum nature of light in the nonlinear optical propagation are still missing many features. We theoretically predict classical spontaneous squeezing of a photon fluid in a nonlocal nonlinear medium. By using the so called Gamow vectors, we show that the quadratures of a coherent state get squeezed and that a maximal squeezing power exists. Our analysis holds true for temporal and spatial optical propagation in highly nonlocal regime. These results open a new scenario in quantum photon fluids and may lead to novel applications in fields like metrology and analogues of quantum gravity.Comment: 6 pages, 2 figure