Pierre Hippolyte Boutigny. The Spheroidal State of Matter Theory

2021 ◽  
Vol 32 (5) ◽  
pp. 201
Author(s):  
Jaime Wisniak
2016 ◽  
Vol 14 (1) ◽  
pp. 125-135
Author(s):  
Patrick J. Connolly

In a recent article Fred Ablondi compares the different approaches to occasionalism put forward by two eighteenth-century Newtonians, Colin Maclaurin and Andrew Baxter. The goal of this short essay is to respond to Ablondi by clarifying some key features of Maclaurin's views on occasionalism and the cause of gravitational attraction. In particular, I explore Maclaurin's matter theory, his views on the explanatory limits of mechanism, and his appeals to the authority of Newton. This leads to a clearer picture of the way in which Maclaurin understood gravitational attraction and the workings of nature.


Universe ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 17
Author(s):  
Nils Andersson

As mature neutron stars are cold (on the relevant temperature scale), one has to carefully consider the state of matter in their interior. The outer kilometre or so is expected to freeze to form an elastic crust of increasingly neutron-rich nuclei, coexisting with a superfluid neutron component, while the star’s fluid core contains a mixed superfluid/superconductor. The dynamics of the star depend heavily on the parameters associated with the different phases. The presence of superfluidity brings new degrees of freedom—in essence we are dealing with a complex multi-fluid system—and additional features: bulk rotation is supported by a dense array of quantised vortices, which introduce dissipation via mutual friction, and the motion of the superfluid is affected by the so-called entrainment effect. This brief survey provides an introduction to—along with a commentary on our current understanding of—these dynamical aspects, paying particular attention to the role of entrainment, and outlines the impact of superfluidity on neutron-star seismology.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Michael J. Landry

Abstract We investigate the phenomenon of second sound in various states of matter from the perspective of non-equilibrium effective field theory (EFT). In particular, for each state of matter considered, we find that at least two (though sometimes multiple) qualitatively different EFTs exist at finite temperature such that there is always at least one EFT with a propagating second-sound wave and at least one with no such second-sound wave. To aid in the construction of these EFTs, we use the method of cosets developed for non-equilibrium systems. It turns out that the difference between the EFTs with and without second-sound modes can be understood as arising from different choices of a new kind of inverse Higgs constraint. Finally, we demonstrate that it is possible to bypass the need for new inverse Higgs constraints by formulating EFTs on a new kind of manifold that is like the usual fluid worldvolume, but with reduced gauge symmetries.


2010 ◽  
Vol 25 (02n03) ◽  
pp. 332-350 ◽  
Author(s):  
IGOR R. KLEBANOV

We provide a brief introduction to the ABJM theory, the level kU(N) × U(N) superconformal Chern-Simons matter theory which has been conjectured to describe N coincident M2 -branes. We discuss its dual formulation in terms of M -theory on AdS4 × S7/ℤk and review some of the evidence in favor of the conjecture. We end with a brief discussion of the important role played by the monopole operators.


1991 ◽  
Vol 158 (5) ◽  
pp. 237-241 ◽  
Author(s):  
G. Seifert ◽  
R. Schmidt ◽  
H.O. Lutz
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document