Results 101 to 110 of about 973 (226)

Hamilton-Jacobi formalism of tachyon inflation and cosmological perturbations

上海师范大学学报. 自然科学版, 2014
We study the cosmological inflation models driven by the rolling tachyon field which has a Born-Infeld-type action.We drive the Hamilton-Jacobi equation for the cosmological dynamics of tachyon inflation and the mode equations for the scalar and tensor ...
LIU Daojun
doaj   +1 more source

Ontological Resilience Beyond Adaptation: Ethical, Relational and Spiritual Practices of a Sufi‐Inspired Rural Community in Türkiye

Tijdschrift voor Economische en Sociale Geografie, Volume 117, Issue 3, Page 449-468, July 2026.
Abstract This paper develops the concept of ontological resilience through an ethnographic study of a Sufi‐inspired rural community in southwestern Türkiye. Based on eight months of fieldwork, it examines how resilience is enacted not as a technical adaptation but as an ethical and spiritual practice of living with vulnerability.
Özge Can Doğmuş
wiley   +1 more source

On the Perturbed Friedmann Equations in Newtonian Gauge

Universe
Based on Newtonian mechanics, in this article, we present a heuristic derivation of the Friedmann equations, providing an intuitive foundation for these fundamental relations in cosmology.
Jaume de Haro, Emilio Elizalde, Supriya Pan   +2 more
doaj   +1 more source

Topological Point Defects in SmC* Liquid Crystals Under Mechanical Disturbance

Advanced Materials Interfaces, Volume 13, Issue 11, 9 June 2026.
Tangetial air jet shear inducess island formation and nucleates topological point defects in uniform SmC films. Island bounded by edge dislocation loops shrink and transform into isolated point defects under continued shear. Mechanical perturbatio provides a controllable route for defect engineering in smectric liquid crystal thin films.
Gunganist Kongklad, Vandana Molahalli, Apichart Pattanaporkratana, Nattaporn Chattham   +3 more
wiley   +1 more source

Slowly Rotating Traversable Wormholes Supported by Radially Varying String‐Fluid Matter: From Regular Geometries to Photon Trajectories

Annalen der Physik, Volume 538, Issue 6, June 2026.
This study examines slowly rotating traversable wormholes supported by string fluids whose properties change with radius. The matter smoothly shifts from a de Sitter‐like core to a string‐dominated exterior, producing a regular, horizon‐free spacetime.
A. Errehymy, B. Turimov, Meraj Ali Khan, S. Usanov, Z. Yasakov, Z. Avezmuratova   +5 more
wiley   +1 more source

Gravity of cosmological perturbations in the CMB [PDF]

Physical Review D, 2006
First, we establish which measures of large-scale perturbations are least afflicted by gauge artifacts and directly map the apparent evolution of inhomogeneities to local interactions of cosmological species. Considering nonlinear and linear perturbations of phase-space distribution, radiation intensity and arbitrary species' density, we require that: (
openaire   +2 more sources

Sleep Disturbances Among Yazidi Survivors of the ISIS Genocide: Epidemiology, Neuropsychology, and Culturally Sensitive Interventions

Brain and Behavior, Volume 16, Issue 6, June 2026.
The figure presents an integrative model of sleep disturbances among Yazidi survivors of the 2014 genocide perpetrated by the Islamic State (ISIS). Genocide‐related trauma, including mass violence, sexual violence, displacement, and historical trauma, is associated with sustained neurobiological dysregulation, including hypothalamic–pituitary–adrenal ...
Jan Ilhan Kizilhan, Zelal Ag, Qanta A. Ahmed, Alon Y. Avidan   +3 more
wiley   +1 more source

Axial gravitational normal modes of uniform density star in Anti-de Sitter spacetime

Nuclear Physics B
The article studies the dynamical behavior of axial gravitational perturbations of homogeneous stars in Anti-de Sitter spacetime. Because the radial coordinate r transforms into the tortoise coordinate y=y(r), obeying y(r=0)=0 and y(r ...
Kai Lin, Alan B. Pavan, Amilcar Rabelo De Queiroz, Elcio Abdalla   +3 more
doaj   +1 more source

Analytical and Numerical Soliton Solutions of the Shynaray II‐A Equation Using the G′G,1G$$ \left(\frac{G^{\prime }}{G},\frac{1}{G}\right) $$‐Expansion Method and Regularization‐Based Neural Networks

Mathematical Methods in the Applied Sciences, Volume 49, Issue 9, Page 9814-9831, June 2026.
ABSTRACT Nonlinear differential equations play a fundamental role in modeling complex physical phenomena across solid‐state physics, hydrodynamics, plasma physics, nonlinear optics, and biological systems. This study focuses on the Shynaray II‐A equation, a relatively less‐explored parametric nonlinear partial differential equation that describes ...
Aamir Farooq, H. W. A. Riaz, Sadique Rehman, M. Mamun Miah, Wen Xiu Ma   +4 more
wiley   +1 more source

BACK REACTION OF COSMOLOGICAL PERTURBATIONS [PDF]

COSMO-99, 2000
The presence of cosmological perturbations affects the background metric and matter configuration in which the perturbations propagate. This effect, studied a long time ago for gravitational waves, also is operational for scalar gravitational fluctuations, inhomogeneities which are believed to be more important in inflationary cosmology.
openaire   +2 more sources