搜索结果: 16-30 共查到“理学 PERTURBATIONS”相关记录115条 . 查询时间(0.044 秒)
The integrated stress response directs cell fate decisions in response to perturbations in protein homeostasis
diabetes cancer
2015/5/25
Disruptions of the endoplasmic reticulum (ER) cause perturbations in protein folding and result in a cellular condition known as ER stress. ER stress and the accumulation of unfolded protein activate ...
Record of Early Toarcian carbon cycle perturbations in a nearshore environment: the Bascharage section (easternmost Paris Basin)
Black shale deposit early Jurassic the negative carbon isotope
2015/1/6
In order to understand the significance of the worldwide deposition of black shale facies in the Early Toarcian (~ 183 Ma), considerable attention has been drawn to this Early Jurassic sub-stage over ...
Two Initial Value Problems Approach for Solving Singular Perturbations Problems
Singular Perturbation Initial Value Problems Asymptotic Power Series Expansions
2013/1/30
In this paper, we presented an initial value approach for solving singularly perturbed two point boundary value problems with the boundary layer at one end (left or right). By employing asymptotic pow...
Quantum Feynman-Kac perturbations
Quantum stochastic cocycle Markovian cocycle quantum stochastic flow one-parameter semigroup
2012/3/1
We develop fully noncommutative Feynman-Kac formulae by employing quantum stochastic processes. To this end we establish some theory for perturbing quantum stochastic flows on von Neumann algebras by ...
Dynamics of Cosmological Perturbations in Multi-Speed Inflation
Dynamics Cosmological Perturbations Multi-Speed Inflation
2011/10/18
We study a multi-field inflationary theory with separable Lagrangian, which has different speed of sound for each field. We find that the fields always coupled at perturbative level through gravitatio...
Local Scale-Dependent Non-Gaussian Curvature Perturbations at Cubic Order
E ective Field Theory Cosmology In ation Non-Gaussianity
2011/10/17
We calculate non-Gaussianities in the bispectrum and trispectrum arising from the cubic term in the local expansion of the scalar curvature perturbation. We compute to three-loop order and for general...
On Shear-Free perturbations of FLRW Universes
On Shear-Free perturbations of FLRW Universes
2011/10/14
A surprising exact result for the Einstein Field Equations is that if pressure-free matter is moving in a shear-free way, then it must be either expansion-free or rotation-free. It has been suggested ...
Compensated Isocurvature Perturbations and the Cosmic Microwave Background
Compensated Isocurvature Perturbations Microwave Background
2011/10/19
Measurements of cosmic microwave background (CMB) anisotropies constrain isocurvature fluctuations between photons and non-relativistic particles to be sub-dominant to adiabatic fluctuations. Perturba...
Recent cosmological observations, including measurements of the CMB anisotropy and the primordial helium abundance, indicate the existence of an extra radiation component in the Universe beyond the st...
Unitary perturbations of compressed N-dimensional shifts
Hardy space model subspaces Aleksandrov disintegration theorem Clark’s unitary peturbations Aleksandrov-Clark measures
2011/9/14
Abstract: Given a purely contractive matrix-valued analytic function $\Theta$ on the unit disc $\bm{D}$, we study the $\mc{U} (n)$-parameter family of unitary perturbations of the operator $Z_\Theta$ ...
Stability of exponential utility maximization with respect to market perturbations
exponential utility maximization market perturbations Portfolio Management
2011/10/8
Abstract: We investigate the continuity of expected exponential utility maximization with respect to perturbation of the Sharpe ratio of markets. By focusing only on continuity, we impose weaker regul...
Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion
nonlinear cosmological perturbation, gauge invariance, non-Gaussianity PACS number(s):98.80.Cq
2011/9/29
In the full nonlinear cosmological perturbation theory in the leading order of the gradient expansion, all the types of the gauge invariant perturbation variables are defined. The metric junction cond...
General conditions for scale-invariant perturbations in an expanding universe
General conditions scale-invariant perturbations expanding universe
2011/9/29
We investigate the general properties of expanding cosmological models which generate scale-invariant curvature perturbations in the presence of a variable speed of sound. We show that in an expanding...
Global-in-time existence of perturbations around travelling-waves
nonlinear and nonlocal conservation law fractional anti-diffusive operator Duhamel formulation travelling-wave global-in-time existence
2011/8/22
Abstract: We investigate a fractional diffusion/anti-diffusion equation proposed by Andrew C. Fowler to describe the dynamics of sand dunes sheared by a fluid flow. In this paper, we prove the global-...
Inverse problems for Jacobi operators II: Mass perturbations of semi-infinite mass-spring systems
Infinite mass-spring system Jacobi matrices Two-spectra inverse problem
2011/7/26
Abstract: We consider an inverse spectral problem for infinite linear mass-spring systems with different configurations obtained by changing the first mass. We give results on the reconstruction of th...