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We study the existence and nonexistence of solitary solutions with different frequencies for a type of nonlinear extension of Dirac-Slater model. There are three main ingredients in this paper. The first is the Pohozaev's identity of nonlinear Dirac equations. Combine with variational identity, we find the nonexistence results when the frequency $\omega$ is greater than $m$. The second is critical point theorem of strongly indefinite functionals. With this, we obtain existence result of $\omega\in (-m,m)$. The third, which is the new main ingredient of this paper, is perturbation of the functional from the second ingredient. Then we can show the existence of solitary solutions when $\omega=-m$. An interesting outcome from our result is that we can see the left and right are completely different in {\it Spectrum Zero Problem} which implies a new phenomenon in quantum theory., Comment: Need modification

This paper investigates the following Keller-Segel-Navier-Stokes system with nonlinear diffusion and rotational flux $$\begin{align}\begin{cases} &n_t+u\cdot\nabla n=\Delta n^m-\nabla\cdot(nS(x, n, c)\nabla c),\quad &x\in \Omega, t>0, \\ &c_t+u\cdot\nabla c=\Delta c-c+n,\quad &x\in \Omega, t>0, \\ &u_t+\kappa (u\cdot\nabla)u+\nabla P=\Delta u+n\nabla \phi,\quad &x\in \Omega, t>0, \\ &\nabla\cdot u=0,\quad &x\in \Omega, t>0, \end{cases}\end{align}$$ where $\kappa\in \mathbb{R},\phi\in W^{2,\infty}(\Omega)$ and $S$ is a given function with values in $\mathbb{R}^{2\times2}$ which fulfills $$ |S(x,n,c)| \leq C_S $$ with some $C _S > 0$. Systems of this type describe chemotaxis-fluid interaction in cases when the evolution of the chemoattractant is essentially dominated by production through cells. If $m>1$ and $\Omega\subset \mathbb{R}^2$ is a {\bf bounded} domain with smooth boundary, then for all reasonably regular initial data, a corresponding initial-boundary value problem for $(KSNF)$ possesses a global and bounded (weak) solution, which significantly improves previous results of several authors. Moreover, the {\bf optimal condition} on the parameter $m$ for global existence is obtained. Our approach underlying the derivation of main result is based on an entropy-like estimate involving the functional %Our main tool is consideration of the energy functional $$\int_{\Omega}(n_{\varepsilon} +\varepsilon)^{m}+\int_{\Omega}|\nabla c_\varepsilon|^{2},$$ where $n_\varepsilon$ and $c_\varepsilon$ are components of the solutions to (2.1) below., Comment: 30 pages. arXiv admin note: text overlap with arXiv:1903.01033

The paper introduces the class of split regular BiHom-Poisson superalgebras, which is a natural generalization of split regular Hom-Poisson algebras and split regular BiHom-Lie superalgebras. By developing techniques of connections of roots for this kind of algebras, we show that such a split regular BiHom-Poisson superalgebras $A$ is of the form $A=U+\sum_{\a}I_\a$ with $U$ a subspace of a maximal abelian subalgebra $H$ and any $I_{\a}$, a well described ideal of $A$, satisfying $[I_\a, I_\b]+I_\a I_\b = 0$ if $[\a]\neq [\b]$. Under certain conditions, in the case of $A$ being of maximal length, the simplicity of the algebra is characterized., Comment: 16 pages. arXiv admin note: text overlap with arXiv:1508.02124, arXiv:1706.07084 by other authors

In this paper, we investigate *-DMP elements in $*$-semigroups and $*$-rings. The notion of *-DMP element was introduced by Patr\'{i}cio in 2004. An element $a$ is *-DMP if there exists a positive integer $m$ such that $a^{m}$ is EP. We first characterize *-DMP elements in terms of the \{1,3\}-inverse, Drazin inverse and pseudo core inverse, respectively. Then, we give the pseudo core decomposition utilizing the pseudo core inverse, which extends the core-EP decomposition introduced by Wang for matrices to an arbitrary $*$-ring; and this decomposition turns to be a useful tool to characterize *-DMP elements. Further, we extend Wang's core-EP order from matrices to $*$-rings and use it to investigate *-DMP elements. Finally, we give necessary and sufficient conditions for two elements $a,~b$ in $*$-rings to have $aa^{\scriptsize\textcircled{\tiny D}}=bb^{\scriptsize\textcircled{\tiny D}}$, which contribute to investigate *-DMP elements., Comment: 17 pages

We present equivalent conditions of reverse order law for the $(b, c)$-inverse $(aw)^{(b,c)}=w^{(b,s)}a^{(t,c)}$ to hold in a ring. Also, we study various mixed-type reverse order laws for the $(b,c)$-inverse. As a consequence, we get results related to the reverse order law for the inverse along an element. More general case of reverse order law $(a_1a_2)^{(b_3, c_3)}=a_2^{(b_2, c_2)}a_1^{(b_1, c_1)}$ is considered too.

In this paper we introduce a new generalized inverse in a ring -- one-sided $(b, c)$-inverse, derived as an extension of $(b, c)$-inverse. This inverse also generalizes one-sided inverse along an element, which was recently introduced by H. H. Zhu et al. [H. H. Zhu, J. L. Chen, P. Patr\'{i}cio, Further results on the inverse along an element in semigroups and rings, Linear Multilinear Algebra, 64 (3) (2016) 393-403]. Also, here we present one-sided annihilator $(b, c)$-inverse, which is an extension of the annihilator $(b, c)$-inverse. Necessary and sufficient conditions for the existence of these new generalized inverses are obtained. Furthermore, we investigate conditions for the existence of one-sided $(b, c)$-inverse of a product of three elements and we consider some properties of one-sided $(b, c)$-inverses.