1,780 research outputs found
Differential operators and their adjoints under integral and multiple point boundary conditions
Differential operators and adjoint systems derived from Green function and Hilbert space
On the Class of Admissable Nonlinearities for Lur'e's Problem
Imposition of conditions on nonlinear function of scalar so that system will be stable or asymptotically stabl
On the Eigenvalues of a Singular Nonself- Adjoint Differential Operator of Second Order
Singular nonself-adjoint differential operator of second order eigenvalue
A general stability criterion for feedback systems
Means for determining stability of feedback systems described by either linear or nonlinear differential equation
Root Locus Asymptotes for the Sum of Two Polynomials of the Same Degree
Root locus asymptotes for sum of two polynomials of same degre
On the Number of L2 Solutions of - y plus Q/t/y Equals Lambda y Where Q/t/ Is Complex Valued
Operator solutions for complex valued second order differential equatio
On the Michailov criterion for exponential polynomials
Michailov criterion for exponential polynomial
Root locus diagrams by digital computer
Adaptation of root locus method to programming on IBM 7074 digital compute
Strongly and Weakly Unstable Anisotropic Quark-Gluon Plasma
Using explicit solutions of the QCD transport equations, we construct an
effective potential for an anisotropic quark-gluon plasma which under plausible
assumptions holds beyond the Hard Loop approximation. The configurations, which
are unstable in the linear response approach, are characterized by a negative
quadratic term of the effective potential. The signs of higher order terms can
be either negative or positive, depending on the parton momentum distribution.
In the case of a Gaussian momentum distribution, the potential is negative and
unbound from below. Therefore, the modes, which are unstable for gauge fields
of small amplitude, remain unstable for arbitrary large amplitudes. We also
present an example of a momentum distribution which gives a negative quadratic
term of the effective potential but the whole potential has a minimum and it
grows for sufficiently large gauge fields. Then, the system is weakly unstable.
The character of the instability is important for the dynamical evolution of
the plasma system.Comment: 13 pages, 1 figure, revised, to appear in Phys. Rev.
Laser scattering by density fluctuations of ultra-cold atoms in a magneto-optical trap
We study the spectrum of density fluctuations in the ultra-cold gas of
neutral atoms, confined in a magneto-optical trap. We determine the
corresponding amplitude and spectra of laser light scattered by this medium. We
derive an expression for the dynamical structure function, by using a test
particle method. We propose to use the collective laser scattering as a
diagnostic method for the microscopic properties of the ultra-cold matter. This
will also allow us to check on the atomic correlations which are mediated by
the collective mean field inside the gas.Comment: J. Phys. B (in press
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