We consider the Hamiltonian of a system of two fermions on a two-dimensional lattice ${\mathbb{Z}}^2$ with a certain type potential. It is proved that the subspace of odd functions $L^o_{ {2}} {(}{\mathbb{T}}^{ {2}} {)}$ is represented as a direct sum of the subspaces $L^{eo}_{ {2}} {(}{\mathbb{T}}^{ {2}} {)}$ and $L^{oe}_{ {2}} {(}{\mathbb{T}}^{ {2}} {)}$, which are invariant under the operator $H(\mathbf {k}) {,\ }\mathbf {k}=(k_1, k_2) \in {\mathbb{T}}^2,$ associated with this Hamiltonian. For any $k_1 \in {({-\pi,}\pi ]}$, it is proved that the operator $H^{eo}(k_1,\pi)=H(k_1,\pi)\big|_{L^{eo}_{ {2}} {(}{\mathbb{T}}^{ {2}} {)}}$ has an infinite number of eigenvalues and for any $k_1 \in ({-\pi,}\pi {)}$, the operator $H^{oe}(k_1,\pi)=H(k_1,\pi)\big|_{L^{oe}_{ {2}} {(}{\mathbb{T}}^{ {2}} {)}}$ has a finite number eigenvalues lying to the left of the essential spectrum. An asymptotic formula is obtained for the number of eigenvalues of the operator $H^{oe}(k_1,\pi)$ as $k_1\rightarrow \pi.$
| Mualliflar | Khalkhuzhaev, A., Makhmudov, Kh., Miyassarov, A. |
|---|---|
| Jurnal | O‘zbekiston matematika jurnali |
| Nashr sanasi | 2026-03-25 |
| Jild | 70 |
| Son | 1 |
| Til | Ingliz |
| DOI | 10.29229/uzmj.2026-1-11 |
DOI: 10.29229/uzmj.2026-1-11 · Maqolaning asl sahifasi
Schr\"{o}dinger operator, lattice, fermion, quasi-momentum, invariant subspaces, essential spectrum, eigenvalue
This work focuses on classifying three-dimensional complex Leibniz dialgebras. We present a complete list of these algebras when the annihilator of the associated Leibniz algebra is one-dimensional.
We consider a model of one-dimensional Schr\"odinger Hamiltonian perturbed by two identical non-local interactions of the form $\delta'(x\pm y)$, symmetrically located at the points $ \pm y$ from the origin. The…
Non-homogeneous Beatty sequence is a sequence of positive integer that taking the floor value of irrational numbers. This paper using the prime counting function, $\pi(x)$ to estimate the cardinality of total distinct…
Let two bounded simply connected domains $D\subset {\mathbb C}_{z}$, $G\subset {\mathbb C}_{w}$, and two locally regular compact subsets $E\subset D,\, \, \, F\subset G$ be given. If $f(z,w)$ is a separately analytic…
This paper investigates the influence of the symmetric product functor $SP^{n}$ and the exponential functor $\exp$ on certain types of continuous mappings, focusing specifically on almost-open and pseudo-open mappings…
In this paper, we aim to study the Cauchy problem posed for a fractional order equation. General solution of the time-fractional equation is found by the Fourier method. The solution to the given problem is shown to be…
A one-dimensional inverse problem for a quasilinear hyperbolic system with an unknown excitation source is considered. The Cauchy problem for a nonlinear Hopf-type system is studied. A Fourier transform is used to…
This article addresses the well-posedness of a coefficient inverse problem for the three-dimensional Tricomi equation in a parallelepiped. For this problem with nonlocal boundary conditions in anisotropic Sobolev…
This paper investigates the antiperiodic boundary value problem for a 2-parabolic equation with a time-deviating argument. A corresponding spectral problem is constructed, the symmetry of the differential operator is…
In the article, high-accuracy difference schemes for the Cauchy problem for a system of fourth-order equations are obtained. Based on the method of energy inequalities, the stability of the scheme is proved, a priori…