Zobrazeno 1 - 10
of 484
pro vyhledávání: '"Papanicolaou, N. A."'
Autor:
Papanicolaou, N C, Christov, I C
Publikováno v:
J. Phys.: Conf. Ser. 2675 (2023) 012016
Sixth-order boundary value problems (BVPs) arise in thin-film flows with a surface that has elastic bending resistance. To solve such problems, we first derive a complete set of odd and even orthonormal eigenfunctions -- resembling trigonometric sine
Externí odkaz:
http://arxiv.org/abs/2308.00673
Publikováno v:
Phys. Rev. B 89, 224418 (2014)
We present a study of the one-dimensional S=1 antiferromagnetic spin chain with large easy plane anisotropy, with special emphasis on field-induced quantum phase transitions. Temperature and magnetic field dependence of magnetization, specific heat,
Externí odkaz:
http://arxiv.org/abs/1404.3064
Publikováno v:
Commun Nonlinear Sci Numer Simulat 19 (2014) 3074-3085
The exhaustive group classification of a class of variable coefficient generalized KdV equations is presented, which completes and enhances results existing in the literature. Lie symmetries are used for solving an initial and boundary value problem
Externí odkaz:
http://arxiv.org/abs/1309.1028
Publikováno v:
Physical Review B 88, 064421 (2013)
We present a theoretical study of the two-dimensional spiral antiferromagnet Ba2CuGe2O7 in the presence of an external magnetic field. We employ a suitable nonlinear sigma model to calculate the T=0 phase diagram and the associated low-energy spin dy
Externí odkaz:
http://arxiv.org/abs/1211.5782
Publikováno v:
Phys. Rev. B 85, 014412 (2012)
The spin-1 anisotropic antiferromagnet NiCl_2-4SC(NH2)_2 exhibits a field-induced quantum phase transition that is formally analogous to Bose-Einstein condensation. Here we present results of systematic high-field electron spin resonance (ESR) experi
Externí odkaz:
http://arxiv.org/abs/1111.5017
Autor:
Komineas, S., Papanicolaou, N.
Publikováno v:
J. Math. Phys. 51, 042705 (2010)
The dynamics of N point vortices in a fluid is described by the Helmholtz-Kirchhoff (HK) equations which lead to a completely integrable Hamiltonian system for N=2 or 3 but chaotic dynamics for N>3. Here we consider a generalization of the HK equatio
Externí odkaz:
http://arxiv.org/abs/0911.2377
Publikováno v:
Phys. Rev. A 72, 053624 (2005)
It has been demonstrated experimentally that non-axially symmetric vortices precess around the centre of a Bose-Einstein condensate. Two types of single vortex states have been observed, usually referred to as the S-vortex and the U-vortex. We study
Externí odkaz:
http://arxiv.org/abs/cond-mat/0508562
Publikováno v:
Phys. Rev. A 72, 053609 (2005)
We derive a class of virial theorems which provide stringent tests of both analytical and numerical calculations of vortex states in a confined Bose-Einstein condensate. In the special case of harmonic confinement we arrive at the somewhat surprising
Externí odkaz:
http://arxiv.org/abs/cond-mat/0508563
Autor:
Chovan, J., Papanicolaou, N.
The layered magnetic compound Ba_2CuGe_2O_7 exhibits spiral antiferromagnetic order thanks to a Dzyaloshinskii-Moriya (DM) anisotropy that is allowed by crystal symmetry. Here we theoretically examine some finer issues such as the experimentally obse
Externí odkaz:
http://arxiv.org/abs/cond-mat/0504262
Publikováno v:
Phys. Rev. B 71, 060405(R) (2005)
We study the fundamental magnetic states of disc-shaped ferromagnetic particles with a uniaxial anisotropy along the symmetry axis. Besides the monodomain, a bidomain state is also identified and studied both numerically and theoretically. This bidom
Externí odkaz:
http://arxiv.org/abs/cond-mat/0409129