A steady smooth Euler flow with support in the vicinity of a helix
In this article we construct a smooth Euler flow supported in a neighborhood of a helix. It may be considered a generalization of a similar solution found by the author for a circle.
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Publications and source records attributed to A. V. Gavrilov.
In this article we construct a smooth Euler flow supported in a neighborhood of a helix. It may be considered a generalization of a similar solution found by the author for a circle.
A nontrivial smooth steady incompressible Euler flow in three dimensions with compact support is constructed. Another uncommon property of this solution is the dependence between the Bernoulli function and the pressure.
We present an analysis of the foundations of the well known Clausius inequality. It is shown that, strictly speaking, the inequality is not a logical consequence of the Kelvin-Planck formulation of the second law of thermodynamics. Some thought experiments demonstrating the violation of the Clausius inequality are considered. Also, a reformulation of the Landauer's principle in terms of the Clausius inequality is proposed. This version of the inequality may be considered a consequence of the fluctuation theorem.
In this paper we study the Taylor series of an operator-valued function related to the differential of the exponential map. For a smooth manifold $\mathcal{M}$ with a torsion-free affine connection the operator $\mathcal{E}_p(v)$ acting on the space $T_p\mathcal{M}$ is defined to be the composition of the differential of the exponential map at $v\in T_p\mathcal{M}$ with parallel transport to $p$ along the geodesic. The Taylor series of $\mathcal{E}_p$ as a function of $v$ is found explicitly in terms of the curvature tensor and its high order covariant derivatives at $p$.
A generalization of the classical Leibniz rule for the covariant derivative on a vector bundle is obtained.
The n-th order covariant derivative on a smooth manifold with an affine connection is a differential operator which turns a function into a tensor field of type (0,n). In this paper the properties of this operatior related to the permutation of indices are investigated by means of non-associative algebra. The general formula for commutation relations of this kind is obtained.
Let $k$ be a field of characteristic $p>0$ and $R$ be a subalgebra of $k[X]=k[x_1,...,x_n]$. Let $J(R)$ be the ideal in $k[X]$ defined by $J(R)Ω_{k[X]/k}^n=k[X]Ω_{R/k}^n$. It is shown that if it is a principal ideal then $J(R)^q$ is a subalgebra of $R[x_1^p,...,x_n^p]$, where $q=p^n(p-1)/2$.
We show that for a metastable system there exists a theoretical possibility of a violation of the Clausius inequality without a violation of the second law. Possibilities of experimental detection of this hypothetical violation are pointed out.
The example of macroscopic thermodynamical system violating the Clausius inequality is presented.