PHASE TRANSITIONS IN HIGHER DIMENSIONAL COSMOLOGY

2010 ◽  
Vol 25 (01) ◽  
pp. 113-122
Author(s):  
RIZWAN UL HAQ ANSARI ◽  
P. K. SURESH

We have considered five-dimensional massive scalar field coupled to gravity and evaluated the one-loop effective potential in higher dimensions. It is demonstrated that nonminimally coupled φ4 theory can be regularized in five dimensions. Temperature dependent one-loop correction and critical temperature βc are computed. The phase transitions in the early universe depend on the space–time curvature R and scalar gravitational coupling ξ. A brief discussion of symmetry restoration is also presented and the nature of phase transitions in the early universe is found to be of second order.

2007 ◽  
Vol 22 (29) ◽  
pp. 5369-5377 ◽  
Author(s):  
RIZWAN UL HAQ ANSARI ◽  
P. K. SURESH

We consider in this paper φ4 theory in higher dimensions. Using functional diagrammatic approach, we compute the one-loop correction to effective potential of the scalar field in five dimensions. It is shown that φ4 theory can be regularized in five dimensions. Temperature dependent one-loop correction and critical temperature βc are computed and βc depends on the fundamental scale [Formula: see text] of the theory. A brief discussion of symmetry restoration is also presented. The nature of phase transitions is examined and is of second order.


1987 ◽  
Vol 02 (05) ◽  
pp. 299-306 ◽  
Author(s):  
H. NISHIMURA ◽  
M. TABUSE

We consider higher dimensional cosmology based on the closed bosonic string theory with the one-loop vacuum energy. It is concluded that the winding-effect of strings around tori has a chance to prevent the extra space from expanding, even though the curvature of torus is zero.


2009 ◽  
Vol 5 (S268) ◽  
pp. 39-40
Author(s):  
S. Chatterjee

AbstractWe investigate nucleosynthesis and element formation in the early universe in the framework of higher dimensional cosmology. We find that temperature decays less rapidly in higher dimensional cosmology, which we believe may have nontrivial consequences vis-a-vis primordial physics.


Author(s):  
Yong Liu ◽  
Kelei Wang ◽  
Juncheng Wei

Abstract We construct a smooth axially symmetric solution to the classical one phase free boundary problem in $\mathbb{R}^{n}$, $n\geq 3.$ Its free boundary is of “catenoid” type. This is a higher dimensional analogy of the Hauswirth–Helein–Pacard solution [18] in $\mathbb{R}^{2}$. The existence of such solution is conjectured in [18, Remark 2.4]. This is the 1st nontrivial smooth solution to the one phase-free boundary problem in higher dimensions.


2005 ◽  
Vol 14 (12) ◽  
pp. 2315-2318 ◽  
Author(s):  
PAUL S. WESSON

Higher-dimensional theories of the kind which may unify gravitation with particle physics can lead to significant modifications of general relativity. In five dimensions, the vacuum becomes non-standard, and the Weak Equivalence Principle becomes a geometrical symmetry which can be broken, perhaps at a level detectable by new tests in space.


Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy

Microcavity polaritons have demonstrated their unique propensity to host macroscopic quantum phenomena. While they appear to be highly promising for applications in a classical realm, they are still far from competing even with decade old electronics. Another playground where polaritons could emerge as strong contenders is the microscopic quantum regime with single-particle effects and nonlinearities at the one-polariton level. Several theoretical proposals exist to explore polariton blockade mechanisms, realize sophisticated quantum phase transitions, implement quantum simulations and/or quantum information processing, thereby opening a new page of the polariton physics when such ideas will be implemented in the laboratory.


2020 ◽  
Vol 8 (1) ◽  
pp. 68-91
Author(s):  
Gianmarco Giovannardi

AbstractThe deformability condition for submanifolds of fixed degree immersed in a graded manifold can be expressed as a system of first order PDEs. In the particular but important case of ruled submanifolds, we introduce a natural choice of coordinates, which allows to deeply simplify the formal expression of the system, and to reduce it to a system of ODEs along a characteristic direction. We introduce a notion of higher dimensional holonomy map in analogy with the one-dimensional case [29], and we provide a characterization for singularities as well as a deformability criterion.


2020 ◽  
Vol 235 (6-7) ◽  
pp. 213-223
Author(s):  
Hilke Petersen ◽  
Lars Robben ◽  
Thorsten M. Gesing

AbstractThe temperature-dependent structure-property relationships of the aluminosilicate perrhenate sodalite |Na8(ReO4)2|[AlSiO4]6 (ReO4-SOD) were analysed via powder X-ray diffraction (PXRD), Raman spectroscopy and heat capacity measurements. ReO4-SOD shows two phase transitions in the investigated temperature range (13 K < T < 1480 K). The first one at 218.6(1) K is correlated to the transition of dynamically ordered $P\overline{4}3n$ (> 218.6(1 K) to a statically disordered (<218.6(1) K) SOD template in $P\overline{4}3n$. The loss of the dynamics of the template anion during cooling causes an increase of disorder, indicated by an unusual intensity decrease of the 011-reflection and an increase of the Re-O2 bond length with decreasing temperature. Additionally, Raman spectroscopy shows a distortion of the ReO4 anion. Upon heating the thermal expansion of the sodalite cage originated in the tilt-mechanism causes the second phase transition at 442(1) K resulting in a symmetry-increase from $P\overline{4}3n$ to $Pm\overline{3}n$, the structure with the sodalites full framework expansion. Noteworthy is the high decomposition temperature of 1320(10) K.


Author(s):  
Simon Engelbert ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Steffen Klenner ◽  
Rainer Pöttgen

Abstract The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.


Sign in / Sign up

Export Citation Format

Share Document