scholarly journals String excitation by initial singularity of inflation

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Kanji Nishii ◽  
Daisuke Yoshida
Keyword(s):  
Hubble Parameter ◽  
Early Stage ◽  
Initial Singularity ◽  
The Past ◽  
Slow Roll ◽  
Oscillation Modes ◽  
The Hill ◽  
Slow Roll Inflation ◽  
Penrose Limit

Abstract We discuss excitation of string oscillation modes by an initial singularity of inflation. The initial singularity of inflation is known to occur with a finite Hubble parameter, which is generally lower than the string scale, and hence it is not clear that stringy effects become significant around it. With the help of Penrose limit, we find that infinitely heavy oscillation modes get excited when a singularity is strong in the sense of Krolak’s classification. We demonstrate that the initial singularities of Starobinsky and hill top inflation, assuming the slow roll inflation to the past infinity, are strong. Hence stringy corrections are inevitable in the very early stage of these inflation models. We also find that the initial singularity of the hill top inflation could be weak for non-slow roll case.

scholarly journals THE POSSIBILITY OF INFLATION IN ASYMPTOTICALLY SAFE GRAVITY

2012 ◽  
Vol 21 (07) ◽  
pp. 1250062 ◽  
Author(s):  
SUNGWOOK E. HONG ◽  
YOUNG JAE LEE ◽  
HEESEUNG ZOE
Keyword(s):  
Phase Space ◽  
Critical Point ◽  
Hubble Parameter ◽  
Relative Energy ◽  
Energy Scale ◽  
Einstein Frame ◽  
Coupling Constants ◽  
Slow Roll ◽  
Slow Roll Inflation

We examine the inflationary modes in the cubic curvature theories in the context of asymptotically safe gravity. On the phase space of the Hubble parameter, there exists a critical point which corresponds to the slow-roll inflation in Einstein frame. Most of the e-foldings are attained around the critical point for each inflationary trajectories. If the coupling constants gi have the parametric relations generated as the power of the relative energy scale of inflation H0 to the cutoff Λ, a successful inflation with more than 60 e-foldings occurs near the critical point.

‘Higher then to her no bookes doe reach’

2018 ◽  
Author(s):  
Martha Vandrei
Keyword(s):  
Early Stage ◽  
Deep Understanding ◽  
Contemporary Philosophy ◽  
James I ◽  
Historical Method ◽  
The Past ◽  
Classical World ◽  
Material Evidence ◽  
Do So

This chapter and the following both draw the reader into seventeenth-century understandings of the past, and of Boudica in particular, and makes clear that in a time before disciplines, writers of ‘history’ were erudite commentators, immersed in political thought, the classical world, and contemporary ideas, as well as in drama, poetry, and the law. Chapter 1 shows the subtleties of Boudica’s place in history at this early stage by giving sustained attention to the work of Edmund Bolton (1574/5–c.1634), the first person to analyse the written and material evidence for Boudica’s deeds, and the last to do so in depth before the later nineteenth century. Bolton’s distaste for contemporary philosophy and his loyalty to James I were highly influential in determining the way the antiquary approached Boudica and her rebellion; but equally important was Bolton’s deep understanding of historical method and the strictures this placed on his interpretive latitude.

scholarly journals Ground Reaction Forces and Kinematics of Ski Jump Landing Using Wearable Sensors

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2011 ◽  
Author(s):  
Bessone ◽  
Petrat ◽  
Schwirtz
Keyword(s):  
Wearable Sensors ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Inertial Motion ◽  
Jump Landing ◽  
The Past ◽  
Landing Biomechanics ◽  
Reaction Forces ◽  
The Hill ◽  
Kinematics And Kinetics

In the past, technological issues limited research focused on ski jump landing. Today, thanks to the development of wearable sensors, it is possible to analyze the biomechanics of athletes without interfering with their movements. The aims of this study were twofold. Firstly, the quantification of the kinetic magnitude during landing is performed using wireless force insoles while 22 athletes jumped during summer training on the hill. In the second part, the insoles were combined with inertial motion units (IMUs) to determine the possible correlation between kinematics and kinetics during landing. The maximal normal ground reaction force (GRFmax) ranged between 1.1 and 5.3 body weight per foot independently when landing using the telemark or parallel leg technique. The GRFmax and impulse were correlated with flying time (p < 0.001). The hip flexions/extensions and the knee and hip rotations of the telemark front leg correlated with GRFmax (r = 0.689, p = 0.040; r = −0.670, p = 0.048; r = 0.820, p = 0.007; respectively). The force insoles and their combination with IMUs resulted in promising setups to analyze landing biomechanics and to provide in-field feedback to the athletes, being quick to place and light, without limiting movement.

scholarly journals Generalized slow-roll inflation

2000 ◽  
Vol 269 (4) ◽  
pp. 209-213 ◽  
Author(s):  
Valerio Faraoni
Keyword(s):  
Slow Roll ◽  
Slow Roll Inflation

Rock carving on Ayodhya Hill: an avenue for geoheritage, geoconservation and environmental sensitization

Ensemble ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 123-131
Author(s):  
Sanjukta Banik ◽  
◽  
Malay Mukhopadhyay ◽  
Keyword(s):  
Narrative Analysis ◽  
Cultural Landscape ◽  
Empirical Observation ◽  
Commercial Use ◽  
The Past ◽  
Nature And Culture ◽  
Future Potential ◽  
Purulia District ◽  
The Hill

The present paper aims to throw light on the environmental sensitivity illustrated through art on a hill signifying interface of nature and culture .Ayodhya Hill in Purulia district, displays an aspect of aesthetic attachment of humans with nature in the form of in-situ rock cut sculpture ‘Pakhi Pahar’which has transformed the bare hill into a piece of art. For the past three decades the hill has been sculpted by a group of local artists, creating around 65 birds.Even the boulders lying on the foot of the hill are sculpted, to save these fragile components of nature from stone quarrying and crushing machines which are demolishing and fragmenting the rocks and hills of the chotanagpur terrain to gather stone chips for commercial use. It may also be argued by a few ,that the natural environment of Matha range of Ayodhya Hill is infringed upon for the sake of art. The present researcher seeks to explain through empirical observation, narrative analysis and perception study of local people whether Pakhi Pahar is an “Aesthetic Regard” or “Aesthetic Affront” for nature . This paper also tries to bring in to focus the future potential of this cultural landscape in developing as a tourism site and giving employment to the local youth.

scholarly journals THE N-TACHYON ASSISTED INFLATION

2007 ◽  
Vol 22 (36) ◽  
pp. 2737-2748 ◽  
Author(s):  
HARVENDRA SINGH
Keyword(s):  
Open String ◽  
Slow Roll ◽  
Slow Roll Inflation

In continuation of the papers hep-th/0505012 and hep-th/0508101 we investigate the consequences when N open-string tachyons roll down simultaneously. We demonstrate that the N-tachyon system coupled to gravity does indeed give rise to the assisted slow-roll inflation.

scholarly journals NATURAL SLOW-ROLL INFLATION

1996 ◽  
Vol 11 (08) ◽  
pp. 631-646 ◽  
Author(s):  
R.F. LANGBEIN ◽  
K. LANGFELD ◽  
H. REINHARDT ◽  
L. von SMEKAL
Keyword(s):  
Phase Change ◽  
Early Universe ◽  
Slow Roll ◽  
Slow Roll Inflation

It is shown that the nonperturbative dynamics of a phase change to the nontrivial phase of λφ4-theory in the early universe can give rise to slow-rollover inflation without recourse to unnaturally small couplings.

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