Research articles

The Instability of a Quantum Superposition of Time Dilations

October 8, 2014

Physics

Quantum Physics

Using the relativistic concept of time dilation we show that a superposition of gravitational potentials can lead to nonunitary time evolution. For sufficiently weak gravitational potentials one can still define, for all intents and purpose...

EnKF-C user guide

October 5, 2014

Computer Science

Computational Engineering, Finance, and Science

EnKF-C provides a compact generic framework for off-line data assimilation into large-scale layered geophysical models with the ensemble Kalman filter (EnKF). It is coded in C for GNU/Linux platform and can work either in EnKF, ensemble opt...

(Weak) $m$ -extremals and $m$ -geodesics

September 26, 2014

Mathematics

Complex Variables

We present a collection of results on (weak)

m

-extremals and

m

-geodesics, concerning general properties, the planar case, quasi-balanced pseudoconvex domains, complex ellipsoids, the Euclidean ball and boundary properties. We prove

3

-...

Reducible deformations and smoothing of primitive multiple curves

September 15, 2014

Mathematics

Algebraic Geometry

A primitive multiple curve is a Cohen-Macaulay irreducible projective curve

Y

that can be locally embedded in a smooth surface, and such that

C=Y_{red}

is smooth. In this case,

L={\mathcal I}_C/{\mathcal I}_C^2

is a line bundle on

C

...

Topological actions of wreath products

September 15, 2014

Mathematics

Geometric Topology

Algebraic Topology

Let

G

and

H

be two groups acting on path connected topological spaces

X

and

Y

respectively. Assume that

H

is finite of order

m

and the quotient maps

p:X\to X/G

and

q:Y\to Y/H

are regular coverings. Then it is well-known that...

Probabilistic well-posedness for the nonlinear wave equation on $B_2\times\mathbb{T}$

September 10, 2014

Mathematics

Physics

Analysis of PDEs

Mathematical Physics

We establish probabilistic well-posedness results for the subcubic nonlinear wave equation, posed on the domain

B_2\times\mathbb{T}

, with randomly chosen initial data having radial symmetry in the

B_2

variable, and with vanishing Dirich...

Convergence of hybrid slice sampling via spectral gap

September 9, 2014

Statistics

Methodology

It is known that the simple slice sampler has robust convergence properties, however the class of problems where it can be implemented is limited. In contrast, we consider hybrid slice samplers which are easily implementable and where anoth...

Symplectic, orthogonal and linear Lie groups in Clifford algebra

September 8, 2014

Physics

Mathematics

Mathematical Physics

In this paper we prove isomorphisms between 5 Lie groups (of arbitrary dimension and fixed signatures) in Clifford algebra and classical matrix Lie groups - symplectic, orthogonal and linear groups. Also we obtain isomorphisms of correspond...

Normal Forms and Degenerate CR Singularities

August 28, 2014

Mathematics

Complex Variables

Differential Geometry

It is constructed a normal form for a class of real-smooth surfaces M\subset\mathbb{C}^{2} defined near a degenerate CR singularity....

Matrix integrals over unitary groups: An application of Schur-Weyl duality

August 16, 2014

Physics

Mathematics

Quantum Physics

Mathematical Physics

The integral formulae pertaining to the unitary group

\mathsf{U}(d)

have been comprehensively reviewed, yielding fresh results and innovative proofs. Central to the derivation of these formulae lies the employment of Schur-Weyl duality, a...

The Instability of a Quantum Superposition of Time Dilations

October 8, 2014

Physics

Quantum Physics

EnKF-C user guide

October 5, 2014

Computer Science

Computational Engineering, Finance, and Science

(Weak) $m$ -extremals and $m$ -geodesics

September 26, 2014

Mathematics

Complex Variables

We present a collection of results on (weak)

m

-extremals and

m

-geodesics, concerning general properties, the planar case, quasi-balanced pseudoconvex domains, complex ellipsoids, the Euclidean ball and boundary properties. We prove

3

-...

Reducible deformations and smoothing of primitive multiple curves

September 15, 2014

Mathematics

Algebraic Geometry

A primitive multiple curve is a Cohen-Macaulay irreducible projective curve

Y

that can be locally embedded in a smooth surface, and such that

C=Y_{red}

is smooth. In this case,

L={\mathcal I}_C/{\mathcal I}_C^2

is a line bundle on

C

...

Topological actions of wreath products

September 15, 2014

Mathematics

Geometric Topology

Algebraic Topology

Let

G

and

H

be two groups acting on path connected topological spaces

X

and

Y

respectively. Assume that

H

is finite of order

m

and the quotient maps

p:X\to X/G

and

q:Y\to Y/H

are regular coverings. Then it is well-known that...

Probabilistic well-posedness for the nonlinear wave equation on $B_2\times\mathbb{T}$

September 10, 2014

Mathematics

Physics

Analysis of PDEs

Mathematical Physics

We establish probabilistic well-posedness results for the subcubic nonlinear wave equation, posed on the domain

B_2\times\mathbb{T}

, with randomly chosen initial data having radial symmetry in the

B_2

variable, and with vanishing Dirich...

Convergence of hybrid slice sampling via spectral gap

September 9, 2014

Statistics

Methodology

Symplectic, orthogonal and linear Lie groups in Clifford algebra

September 8, 2014

Physics

Mathematics

Mathematical Physics

Normal Forms and Degenerate CR Singularities

August 28, 2014

Mathematics

Complex Variables

Differential Geometry

It is constructed a normal form for a class of real-smooth surfaces M\subset\mathbb{C}^{2} defined near a degenerate CR singularity....

Matrix integrals over unitary groups: An application of Schur-Weyl duality

August 16, 2014

Physics

Mathematics

Quantum Physics

Mathematical Physics

The integral formulae pertaining to the unitary group

\mathsf{U}(d)

have been comprehensively reviewed, yielding fresh results and innovative proofs. Central to the derivation of these formulae lies the employment of Schur-Weyl duality, a...

The Instability of a Quantum Superposition of Time Dilations

EnKF-C user guide

(Weak) mmm-extremals and mmm-geodesics

Reducible deformations and smoothing of primitive multiple curves

Topological actions of wreath products

Probabilistic well-posedness for the nonlinear wave equation on B2×TB_2\times\mathbb{T}B2​×T

Convergence of hybrid slice sampling via spectral gap

Symplectic, orthogonal and linear Lie groups in Clifford algebra

Normal Forms and Degenerate CR Singularities

Matrix integrals over unitary groups: An application of Schur-Weyl duality

The Instability of a Quantum Superposition of Time Dilations

EnKF-C user guide

(Weak) mmm-extremals and mmm-geodesics

Reducible deformations and smoothing of primitive multiple curves

Topological actions of wreath products

Probabilistic well-posedness for the nonlinear wave equation on B2×TB_2\times\mathbb{T}B2​×T

Convergence of hybrid slice sampling via spectral gap

Symplectic, orthogonal and linear Lie groups in Clifford algebra

Normal Forms and Degenerate CR Singularities

Matrix integrals over unitary groups: An application of Schur-Weyl duality

(Weak) $m$ -extremals and $m$ -geodesics

Probabilistic well-posedness for the nonlinear wave equation on $B_2\times\mathbb{T}$

(Weak) $m$ -extremals and $m$ -geodesics

Probabilistic well-posedness for the nonlinear wave equation on $B_2\times\mathbb{T}$