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Schroedinger uncertainty relation and its minimization states  [PDF]
D. A. Trifonov
Physics , 2001,
Abstract: An introductory survey on the Schroedinger uncertainty relation and its minimization states is presented with minimal number of formulas and some historical points. The case of the two canonical observables, position and momentum, is discussed in greater detail: basic properties of the two subsets of minimization states (canonical squeezed and coherent states) are reviewed and compared. The case of two non-canonical observables is breafly outlined. Stanfard SU(1,1) and SU(2) group-related coherent states can be defined as states that minimize Schroedinger inequality for the three pairs of generators simultaneously. The symmetry of the Heisenberg and Schroedinger relations is also discussed, and two natural generalizations to the cases of several observables and several states are noted.
A Simple Derivation of Schroedinger Uncertainty Relation  [PDF]
Gustavo Rigolin
Physics , 2005, DOI: 10.1088/0143-0807/36/6/065007
Abstract: We show how the Schroedinger Uncertainty Relation for a pair of observables can be deduced using the Cauchy-Schwarz inequality plus successive applications of the commutation relation involving the two observables. Our derivation differs from the original one in the sense that we do not need the expansion of the product of these two observables in a sum of symmetrical and anti-symmetrical operators.
Ground and excited scalar isoscalar meson states in a U(3)xU(3) quark model with a glueball  [PDF]
M. K. Volkov,V. L. Yudichev
Physics , 2001, DOI: 10.1007/s100500170134
Abstract: Ground and first radially excited scalar isoscalar meson states and a scalar glueball are described in a nonlocal U(3)xU(3) quark model. The glueball is introduced into the effective meson Lagrangian by means of the dilaton model on the base of the scale invariance of the meson Lagrangian. The scale invariance breaking by current quark masses and gluon anomalies is taken into account. The glueball anomalies turn out to be important for the description of the glueball-quarkonia mixing. The masses of five scalar isoscalar meson states and their strong decay widths are calculated. The state f_0(1500) is shown to be composed mostly of the scalar glueball.
Selection of the ground state for nonlinear Schroedinger equations  [PDF]
A. Soffer,M. I. Weinstein
Physics , 2003, DOI: 10.1142/S0129055X04002175
Abstract: We prove for a class of nonlinear Schr\"odinger systems (NLS) having two nonlinear bound states that the (generic) large time behavior is characterized by decay of the excited state, asymptotic approach to the nonlinear ground state and dispersive radiation. Our analysis elucidates the mechanism through which initial conditions which are very near the excited state branch evolve into a (nonlinear) ground state, a phenomenon known as {\it ground state selection}. Key steps in the analysis are the introduction of a particular linearization and the derivation of a normal form which reflects the dynamics on all time scales and yields, in particular, nonlinear Master equations. Then, a novel multiple time scale dynamic stability theory is developed. Consequently, we give a detailed description of the asymptotic behavior of the two bound state NLS for all small initial data. The methods are general and can be extended to treat NLS with more than two bound states and more general nonlinearities including those of Hartree-Fock type.
On the Relation Between Fock and Schroedinger Representations for a Scalar Field  [PDF]
Alejandro Corichi,Jeronimo Cortez,Hernando Quevedo
Physics , 2002, DOI: 10.1016/j.aop.2004.05.004
Abstract: Linear free field theories are one of the few Quantum Field Theories that are exactly soluble. There are, however, (at least) two very different languages to describe them, Fock space methods and the Schroedinger functional description. In this paper, the precise sense in which the two representations are related is reviewed. Several properties of these representations are studied, among them the well known fact that the Schroedinger counterpart of the usual Fock representation is described by a Gaussian measure. A real scalar field theory is considered, both on Minkowski spacetime for arbitrary, non-inertial embeddings of the Cauchy surface, and for arbitrary (globally hyperbolic) curved spacetimes. As a concrete example, the Schroedinger representation on stationary and homogeneous cosmological spacetimes is constructed.
Threshold phenomena and existence results for NLS ground states on graphs  [PDF]
Riccardo Adami,Enrico Serra,Paolo Tilli
Mathematics , 2015,
Abstract: We investigate the existence of ground states of prescribed mass, for the nonlinear Schroedinger energy on a noncompact metric graph G. While in some cases the topology of G may rule out or, on the contrary, guarantee the existence of ground states of any given mass, in general also some metric properties of G, and their quantitative relation with the actual value of the prescribed mass, are relevant as concerns the existence of ground states. This may give rise to interesting phase transitions from nonexistence to existence of ground states, when a certain quantity reaches a critical threshold.
A lower bound for the ground state energy of a Schroedinger operator on a loop  [PDF]
Helmut Linde
Mathematics , 2005,
Abstract: Consider a one dimensional quantum mechanical particle described by the Schroedinger equation on a closed curve of length $2\pi$. Assume that the potential is given by the square of the curve's curvature. We show that in this case the energy of the particle can not be lower than 0.6085. We also prove that it is not lower than 1 (the conjectured optimal lower bound) for a certain class of closed curves that have an additional geometrical property
Pendulum View of The Schroedinger Equation  [PDF]
Biao Wu
Physics , 2003,
Abstract: A transformation is found between the one dimensional Schroedinger equation and a pendulum problem. It is demonstrated how to construct exact solutions with the resulted pendulum equation. The relation of this transformation to the Zakharov-Shabat equations is pointed out.
Asymptotic stability of ground states in 3D nonlinear Schroedinger equation including subcritical cases  [PDF]
E. Kirr,?. M?zrak
Mathematics , 2008,
Abstract: We consider a class of nonlinear Schroedinger equation in three space dimensions with an attractive potential. The nonlinearity is local but rather general encompassing for the first time both subcritical and supercritical (in $L^2$) nonlinearities. We study the asymptotic stability of the nonlinear bound states, i.e. periodic in time localized in space solutions. Our result shows that all solutions with small initial data, converge to a nonlinear bound state. Therefore, the nonlinear bound states are asymptotically stable. The proof hinges on dispersive estimates that we obtain for the time dependent, Hamiltonian, linearized dynamics around a careful chosen one parameter family of bound states that "shadows" the nonlinear evolution of the system. Due to the generality of the methods we develop we expect them to extend to the case of perturbations of large bound states and to other nonlinear dispersive wave type equations.
Precanonical Quantization and the Schroedinger Wave Functional  [PDF]
I. V. Kanatchikov
Physics , 2000, DOI: 10.1016/S0375-9601(01)00225-0
Abstract: A relation between the Schroedinger wave functional and the Clifford-valued wave function which appears in what we call precanonical quantization of fields and fulfills a Dirac-like generalized covariant Schroedinger equation on the space of field and space-time variables is discussed. The Schroedinger wave functional is argued to be the trace of the positive frequency part of the continual product over all spatial points of the values of the aforementioned wave function restricted to a Cauchy surface. The standard functional differential Schroedinger equation is derived as a consequence of the Dirac-like covariant Schroedinger equation.
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