Log in

Relevant bibliographies by topics / Primordial phase / Journal articles

To see the other types of publications on this topic, follow the link: Primordial phase.

Journal articles on the topic 'Primordial phase'

Author: Grafiati

Published: 28 May 2022

Last updated: 31 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Primordial phase.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Occhionero, Franco, Luca Amendola, and Pier Stefano Corasaniti. "Primordial Bubbles within Primordial Bubbles." Symposium - International Astronomical Union 201 (2005): 497–98. http://dx.doi.org/10.1017/s0074180900216847.

Full text

Abstract:

Two consecutive, distinct episodes of phase transition occurring during inflation may nucleate two generations of bubbles, one inside the other. We design a model of inflation that realizes this sequence and yields bubble spectra that are bimodal and tunable functions of phenomelogical parameters in turn combinations of microphysical parameters. We argue in favor of a tuning of the parameters such that the outer and earlier generation of bubbles becomes hundreds of Mpc/h in diameter (like the local Hubble bubbles of the literature) whereas the inner and later generation becomes tens of Mpc/h i

APA, Harvard, Vancouver, ISO, and other styles

2

Stahler, S. W., F. Palla, and E. E. Salpeter. "Primordial stellar evolution - The protostar phase." Astrophysical Journal 302 (March 1986): 590. http://dx.doi.org/10.1086/164018.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Alvarenga, Flávio Gimenes, and Júlio César Fabris. "Primordial cosmology with a contraction phase." Classical and Quantum Gravity 12, no. 8 (1995): L69—L74. http://dx.doi.org/10.1088/0264-9381/12/8/001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Audouze, J. "Primordial Nucleosynthesis." Transactions of the International Astronomical Union 20, no. 1 (1988): 658–60. http://dx.doi.org/10.1017/s0251107x00007501.

Full text

Abstract:

Primordial nucleosynthesis which is responsible for the formation of the lightest elements (D, 3He, 4HE and 7Li) might be as important as the overall expansion of the Universe and the cosmic background radiation to prove the occurrence of a dense and hot phase for the Unvierse about 15 billion years ago. As recalled in many reviews (e.g. refs. 1, 2) the standard Big Bang nucleosynthesis leads to two important conclusions regarding (i) a limitation of the baryonic density such that the corresponding cosmological parameter ΩB ≤ 0.1; (ii) a limitation of the number of neutrino flavours to 3-4 con

APA, Harvard, Vancouver, ISO, and other styles

5

Pritchard, Xavier, and Christian T. Byrnes. "Constraining the impact of standard model phase transitions on primordial black holes." Journal of Cosmology and Astroparticle Physics 2025, no. 01 (2025): 076. https://doi.org/10.1088/1475-7516/2025/01/076.

Full text

Abstract:

Abstract Phase transitions in the early universe lead to a reduction in the equation of state of the primordial plasma. This exponentially enhances the formation rate of primordial black holes. However, this sensitivity to the equation of state is the same that primordial black hole abundances show to the primordial curvature power spectrum amplitude. In this paper, we investigate peaked power spectra and show the challenges associated with motivating populations of primordial black holes with standard model enhancements. The parametrisation of different power spectra plays an important role i

APA, Harvard, Vancouver, ISO, and other styles

6

Balaji, Shyam, Guillem Domènech, and Joseph Silk. "Induced gravitational waves from slow-roll inflation after an enhancing phase." Journal of Cosmology and Astroparticle Physics 2022, no. 09 (2022): 016. http://dx.doi.org/10.1088/1475-7516/2022/09/016.

Full text

Abstract:

Abstract The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in multi-field space. However, in many models, inflation does not end immediately after the enhancing feature and it is likely to continue with a second phase of slow-roll. We show that the resulting induced gravitational waves may probe the primordial spectrum from the second inflationary phase, even if its amplitude is too small to directly induce detectable

APA, Harvard, Vancouver, ISO, and other styles

7

LAI, XIAOYU, and RENXIN XU. "PRIMORDIAL STRANGE QUARK MATTER." International Journal of Modern Physics E 20, supp01 (2011): 158–66. http://dx.doi.org/10.1142/s0218301311040207.

Full text

Abstract:

Strange quark nuggets (SQNs) could be the relics of the cosmological QCD phase transition, and they could very likely be the candidate of cold dark matter if survived the cooling of the later Universe, although the formation and evolution of these SQNs depend on the physical state of the hot QGP (quark-gluon plasma) phase and the state of cold quark matter. We reconsider the possibility of SQNs as cold dark matter, and discuss the astrophysical consequences of primordial SQNs in the early and present universe. In the early Universe, the formation of black holes inside primordial halos could be

APA, Harvard, Vancouver, ISO, and other styles

8

LIU LIAO. "PRIMORDIAL BLACK HOLE FORMATION IN INFLATIONARY PHASE." Acta Physica Sinica 35, no. 3 (1986): 375. http://dx.doi.org/10.7498/aps.35.375.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Banerjee, Indra Kumar, and Ujjal Kumar Dey. "Probing the origin of primordial black holes through novel gravitational wave spectrum." Journal of Cosmology and Astroparticle Physics 2023, no. 07 (2023): 024. http://dx.doi.org/10.1088/1475-7516/2023/07/024.

Full text

Abstract:

Abstract In this article we investigate the cumulative stochastic gravitational wave spectra as a tool to gain insight on the creation mechanism of primordial black holes. We consider gravitational waves from the production mechanism of primordial black holes and from the gravitational interactions of those primordial black holes among themselves and other astrophysical black holes. We specifically focus on asynchronous bubble nucleation during a first order phase transition as the creation mechanism. We have used two benchmark phase transitions through which the primordial black holes and the

APA, Harvard, Vancouver, ISO, and other styles

10

ENQVIST, KARI. "PRIMORDIAL MAGNETIC FIELDS." International Journal of Modern Physics D 07, no. 03 (1998): 331–49. http://dx.doi.org/10.1142/s0218271898000243.

Full text

Abstract:

The explanation of the observed galactic magnetic fields may require the existence of a primordial magnetic field. Such a field may arise during the early cosmological phase transitions, or because of other particle physics related phenomena in the very early universe reviewed here. The turbulent evolution of the initial, randomly fluctuating microscopic field to a large-scale macroscopic field can be described in terms of a shell model, which provides an approximation to the complete magnetohydrodynamics. The results indicate that there is an inverse cascade of magnetic energy whereby the coh

APA, Harvard, Vancouver, ISO, and other styles

11

Bianchi, Eugenio, Lucas Hackl, and N. Yokomizo. "Entanglement time in the primordial universe." International Journal of Modern Physics D 24, no. 12 (2015): 1544006. http://dx.doi.org/10.1142/s021827181544006x.

Full text

Abstract:

We investigate the behavior of the entanglement entropy of space in the primordial phase of the universe before the beginning of the cosmic inflation. We argue that in this phase the entanglement entropy of a region of space grows from a zero-law to an area-law. This behavior provides a quantum version of the classical Belinsky–Khalatnikov–Lifshitz (BKL) conjecture that spatially separated points decouple in the approach to a cosmological singularity. We show that the relational growth of the entanglement entropy with the scale factor provides a new statistical notion of arrow of time in quant

APA, Harvard, Vancouver, ISO, and other styles

12

Moniruzzaman, Mohammad, Jibak Lee, Mai Zengyo, and Takashi Miyano. "Knockdown of FOXO3 induces primordial oocyte activation in pigs." REPRODUCTION 139, no. 2 (2010): 337–48. http://dx.doi.org/10.1530/rep-09-0207.

Full text

Abstract:

Mammalian ovaries are endowed with a large number of primordial follicles, each containing a nongrowing oocyte. Only a small population of primordial oocytes (oocytes in primordial follicles) is activated to enter the growth phase throughout a female's reproductive life. Little is known about the mechanism regulating the activation of primordial oocytes. Here, we found that the primordial oocytes from infant pigs (10- to 20-day-old) grew to full size at 2 months after xenografting to immunodeficient mice, whereas those from prepubertal pigs (6-month-old) survived without initiation of their gr

APA, Harvard, Vancouver, ISO, and other styles

13

Stahler, S. W., F. Palla, and E. E. Salpeter. "Primordial stellar evolution - The pre-main-sequence phase." Astrophysical Journal 308 (September 1986): 697. http://dx.doi.org/10.1086/164542.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Alcock, C., G. M. Fuller, and G. J. Mathews. "The quark-hadron phase transition and primordial nucleosynthesis." Astrophysical Journal 320 (September 1987): 439. http://dx.doi.org/10.1086/165560.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Xie, Kepan. "Primordial black holes from an electroweak phase transition." Nuclear and Particle Physics Proceedings 330-335 (July 2023): 8. http://dx.doi.org/10.1016/j.nuclphysbps.2023.04.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

NOVELLO, MÁRIO, and LUCIANE R. DE FREITAS. "FLUCTUATIONS IN A PRIMORDIAL ANISOTROPIC ERA." International Journal of Modern Physics A 13, no. 03 (1998): 363–79. http://dx.doi.org/10.1142/s0217751x98000159.

Full text

Abstract:

The primordial Universe is treated in terms of a nonperfect fluid configuration endowed with an anisotropic expansion. The deGennes–Landau mechanism of phase transition acts as a very efficient process to provide the elimination of the previous anisotropy and to set the universe in the current isotropic FRW stage. The entropy produced, as a consequence of the phase transition, depends on the strength of the previous shear. We suggest the hypothesis that the germinal perturbations that will grow into the observed system of galaxies occurring in the anisotropic era. We present a model to deal wi

APA, Harvard, Vancouver, ISO, and other styles

17

Harada, Tomohiro. "Primordial Black Holes: Formation, Spin and Type II." Universe 10, no. 12 (2024): 444. https://doi.org/10.3390/universe10120444.

Full text

Abstract:

Primordial black holes (PBHs) may have formed through the gravitational collapse of cosmological perturbations that were generated and stretched during the inflationary era, later entering the cosmological horizon during the decelerating phase, if their amplitudes were sufficiently large. In this review paper, we will briefly introduce the basic concept of PBHs and review the formation dynamics through this mechanism, the estimation of the initial spins of PBHs and the time evolution of type II fluctuations, with a focus on the radiation-dominated and (early) matter-dominated phases.

APA, Harvard, Vancouver, ISO, and other styles

18

Franciolini, G., A. Ianniccari, A. Kehagias, D. Perrone, and A. Riotto. "Renormalized primordial black holes." Journal of Cosmology and Astroparticle Physics 2024, no. 11 (2024): 001. http://dx.doi.org/10.1088/1475-7516/2024/11/001.

Full text

Abstract:

Abstract The formation of primordial black holes in the early universe may happen through the collapse of large curvature perturbations generated during a non-attractor phase of inflation or through a curvaton-like dynamics after inflation. The fact that such small-scale curvature perturbation is typically non-Gaussian leads to the renormalization of composite operators built up from the smoothed density contrast and entering in the calculation of the primordial black abundance. Such renormalization causes the phenomenon of operator mixing and the appearance of an infinite tower of local, non-

APA, Harvard, Vancouver, ISO, and other styles

19

MASPERI, LUIS, and MILVA ORSARIA. "PRIMORDIAL BUBBLES OF COLOUR SUPERCONDUCTING QUARK MATTER." International Journal of Modern Physics D 13, no. 07 (2004): 1361–64. http://dx.doi.org/10.1142/s0218271804005547.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Belgacem, Enis, Giulia Cusin, Stefano Foffa, Michele Maggiore, and Michele Mancarella. "Stability issues of nonlocal gravity during primordial inflation." International Journal of Modern Physics A 33, no. 01 (2018): 1850007. http://dx.doi.org/10.1142/s0217751x18500070.

Full text

Abstract:

We study the cosmological evolution of some nonlocal gravity models, when the initial conditions are set during a phase of primordial inflation. We examine in particular three models, the so-called RT, RR and [Formula: see text] models, previously introduced by our group. We find that, during inflation, the RT model has a viable background evolution, but at the level of cosmological perturbations develops instabilities that make it nonviable. In contrast, the RR and [Formula: see text] models have a viable evolution even when their initial conditions are set during a phase of primordial inflat

APA, Harvard, Vancouver, ISO, and other styles

21

CHENG, SHU-LIN, WO-LUNG LEE, and KIN-WANG NG. "PRIMORDIAL MAGNETIC FIELDS BY COSMIC INFLATION." International Journal of Modern Physics: Conference Series 12 (January 2012): 264–71. http://dx.doi.org/10.1142/s2010194512006460.

Full text

Abstract:

Contrary to the conventional wisdom, we find that it is plausible to generate primordial magnetic seed fields via spinodal instability efficiently during cosmic inflation provided that a fast-roll stage is involved before the inflaton entering into the slow-roll phase. Moreover, the primordial magnetic field produced in such a mechanism can be used to constrain the low quadrupole moment of Cosmic Microwave Background.

APA, Harvard, Vancouver, ISO, and other styles

22

Firouzjahi, Hassan, and Antonio Riotto. "Primordial Black Holes and loops in single-field inflation." Journal of Cosmology and Astroparticle Physics 2024, no. 02 (2024): 021. http://dx.doi.org/10.1088/1475-7516/2024/02/021.

Full text

Abstract:

Abstract Using the δN formalism we calculate the one-loop correction to the large-scale power spectrum of the curvature perturbation in the standard scenario where primordial black holes are formed in the early universe thanks to a phase of ultra-slow-roll in single-field inflation. We explicitly show that one-loop corrections are negligible when the transition from the ultra-slow-roll to the slow-roll phase is smooth. We conclude that the PBH formation scenario through a ultra-slow-roll phase is viable.

APA, Harvard, Vancouver, ISO, and other styles

23

FABRIS, J., and Ph SPINDEL. "SCALAR PERTURBATIONS IN A PRIMORDIAL INFLATIONARY SCENARIO." International Journal of Modern Physics A 17, no. 20 (2002): 2758. http://dx.doi.org/10.1142/s0217751x02011850.

Full text

Abstract:

We compute the spectral index for scalar perturbations generated in a primordial inflationary model2. In this model, the transition of the inflationary phase to the radiative era is achieved through the decay of the cosmological term leading a second order phase transition and the characteristics of the model allow to implement a set of initial conditions where the perturbations display a thermal spectrum when they emerge from the horizon. [Formula: see text] The obtained value for the spectral index is equal to 2, a result that depends very weakly on the various parameters of the model and on

APA, Harvard, Vancouver, ISO, and other styles

24

FABRIS, Júlio C., Richard KERNER, and Joël TOSSA. "PHASE DIAGRAMS OF MULTIDIMENSIONAL COSMOLOGICAL MODELS." International Journal of Modern Physics D 03, no. 01 (1994): 181–85. http://dx.doi.org/10.1142/s0218271894000241.

Full text

Abstract:

We work out the phase diagram for a multidimensional cosmological model based on the Seven Dimensional Supergravity. From this phase diagram, we can study a possible scenario for a post- inflationary phase. We study also the evolution of scalar perturbations in this primordial scenario.

APA, Harvard, Vancouver, ISO, and other styles

25

Tumurtushaa, Gansukh, Seoktae Koh, and Bum-Hoon Lee. "Suppression of the Primordial Gravitational Waves." International Journal of Modern Physics: Conference Series 43 (January 2016): 1660204. http://dx.doi.org/10.1142/s2010194516602040.

Full text

Abstract:

We study the primordial gravitational waves induced by space-space condensate inflation model. For modes that cross the comoving horizon during matter dominated era, we calculate the energy spectrum of gravitational waves. The energy spectrum of gravitational waves for our model has significantly suppressed in the low frequency range. The suppression occurs due to the phase transition during the early evolution of the Universe and depends on model parameter.

APA, Harvard, Vancouver, ISO, and other styles

26

Wu, Yi-Peng, and Jun'ichi Yokoyama. "Loop corrections to primordial fluctuations from inflationary phase transitions." Journal of Cosmology and Astroparticle Physics 2018, no. 05 (2018): 009. http://dx.doi.org/10.1088/1475-7516/2018/05/009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Sigl, Günter, Angela V. Olinto, and Karsten Jedamzik. "Primordial magnetic fields from cosmological first order phase transitions." Physical Review D 55, no. 8 (1997): 4582–90. http://dx.doi.org/10.1103/physrevd.55.4582.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Lesgourgues, J., David Polarski, and Alexei A. Starobinsky. "On the phase-space volume of primordial cosmological perturbations." Classical and Quantum Gravity 14, no. 4 (1997): 881–88. http://dx.doi.org/10.1088/0264-9381/14/4/006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Barroso, E. J., L. F. Demétrio, S. D. P. Vitenti, and Xuan Ye. "Primordial black hole formation in a dust bouncing model." Journal of Cosmology and Astroparticle Physics 2025, no. 01 (2025): 052. https://doi.org/10.1088/1475-7516/2025/01/052.

Full text

Abstract:

Abstract Linear scalar cosmological perturbations have increasing spectra in the contracting phase of bouncing models. We study the conditions for which these perturbations may collapse into primordial black holes and the hypothesis that these objects constitute a fraction of dark matter. We compute the critical density contrast that describes the collapse of matter perturbations in the flat-dust bounce model with a parametric solution, obtained from the Lemaitre-Tolman-Bondi metric that represents the spherical collapse. We discuss the inability of the Newtonian gauge to describe perturbation

APA, Harvard, Vancouver, ISO, and other styles

30

Gomez-Aguilar, Tadeo D., Luis E. Padilla, Encieh Erfani, and Juan Carlos Hidalgo. "Constraints on primordial black holes for nonstandard cosmologies." Journal of Cosmology and Astroparticle Physics 2024, no. 11 (2024): 005. http://dx.doi.org/10.1088/1475-7516/2024/11/005.

Full text

Abstract:

Abstract We study how the bounds on the abundance of Primordial Black Holes (PBHs) and the constraints on power spectrum are modified if a non-standard evolution phase takes place between the end of inflation and the Standard radiation-dominated (RD) universe after inflation. The constraints on PBH abundance and power spectrum are computed using the new, freely available, https://github.com/TadeoDGAguilar/PBHBeta PBHBeta library, which accounts for the effects of non-standard expansion and specific criteria for PBH formation in such non-standard scenarios. As working examples, we consider thre

APA, Harvard, Vancouver, ISO, and other styles

31

Ballesteros, Guillermo, and Jesús Gambín Egea. "One-loop power spectrum in ultra slow-roll inflation and implications for primordial black hole dark matter." Journal of Cosmology and Astroparticle Physics 2024, no. 07 (2024): 052. http://dx.doi.org/10.1088/1475-7516/2024/07/052.

Full text

Abstract:

Abstract We apply the in-in formalism to address the question of whether the size of the one-loop spectrum of curvature fluctuations in ultra-slow-roll inflation models designed for producing a large population of primordial black holes implies a breakdown of perturbation theory. We consider a simplified piece-wise description of inflation, in which the ultra-slow-roll phase is preceded and followed by slow-roll phases linked by transitional periods. We work in the δϕ-gauge, including all relevant cubic and quartic interactions and the necessary counterterms to renormalize the ultraviolet dive

APA, Harvard, Vancouver, ISO, and other styles

32

Padilla, Luis E., Juan Carlos Hidalgo, Karim A. Malik, and David Mulryne. "Detecting the stochastic gravitational wave background from primordial black holes in slow-reheating scenarios." Journal of Cosmology and Astroparticle Physics 2024, no. 12 (2024): 011. https://doi.org/10.1088/1475-7516/2024/12/011.

Full text

Abstract:

Abstract After primordial inflation, the universe may have experienced a prolonged reheating epoch, potentially leading to a phase of matter domination supported by the oscillating inflaton field. During such an epoch, perturbations in the inflaton virialize upon reentering the cosmological horizon, forming inflaton structures. If the primordial overdensities are sufficiently large, these structures collapse to form primordial black holes (PBHs). To occur at a significant rate, this process requires an enhanced primordial power spectrum (PPS) at small scales. The enhancement of the PPS, as wel

APA, Harvard, Vancouver, ISO, and other styles

33

Reeves, Hubert. "The status of Big Bang nucleosynthesis in July 1988." Highlights of Astronomy 8 (1989): 693–96. http://dx.doi.org/10.1017/s1539299600008674.

Full text

Abstract:

Important progresses have been made in two fronts in the few past years.On the theoretical ground, we have realized the importance of the quark-hadron phase transition as possibly influencing in a major way the yields of die primordial nucleosynthesis isotopes.On the observational ground, the status of lithium as a bona-fide cosmological observable has been confirmed and its primordial abundance can be evaluated with increased confidence.

APA, Harvard, Vancouver, ISO, and other styles

34

SRIVASTAVA, S. K. "THE RICCION, THE INSTANTON AND PRIMORDIAL INFLATION." International Journal of Modern Physics A 14, no. 06 (1999): 875–84. http://dx.doi.org/10.1142/s0217751x99000427.

Full text

Abstract:

It is shown that R2 and R3 terms dominate over the Einstein–Hilbert term in the gravitational action till the energy mass scale M ≥ 8.4 × 108 GeV. In the presence of these higher derivative terms, the action for Riccions is obtained with quartic self-interaction potential. It is interesting to see that the instanton solution for Riccions gives rise to primordial inflation without any phase transition or symmetry breaking.

APA, Harvard, Vancouver, ISO, and other styles

35

Cherchneff, Isabelle, and Simon Lilly. "Molecules in nearby and primordial supernovae." Proceedings of the International Astronomical Union 4, S251 (2008): 221–26. http://dx.doi.org/10.1017/s1743921308021625.

Full text

Abstract:

AbstractWe present new chemical models of supernova (SN) ejecta based on a chemical kinetic approach. We focus on the formation of inorganic and organic molecules including gas phase dust precursors, and consider zero-metallicity progenitor, massive supernovae and nearby core-collapse supernovae such as SN1987A. We find that both types are forming large amounts of molecules in their ejecta at times as early as 200 days after explosion. Upper limits on the dust formation budget are derived. Our results on dust precursors do not agree with existing studies on dust condensation in SN ejecta. We c

APA, Harvard, Vancouver, ISO, and other styles

36

Mtchedlidze, Salome, Paola Domínguez-Fernández, Xiaolong Du, et al. "Inflationary and Phase-transitional Primordial Magnetic Fields in Galaxy Clusters." Astrophysical Journal 944, no. 1 (2023): 100. http://dx.doi.org/10.3847/1538-4357/acb04d.

Full text

Abstract:

Abstract Primordial magnetic fields (PMFs) are possible candidates for explaining the observed magnetic fields in galaxy clusters. Two competing scenarios of primordial magnetogenesis have been discussed in the literature: inflationary and phase-transitional. We study the amplification of both large- and small-scale correlated magnetic fields, corresponding to inflation- and phase transition–generated PMFs, in a massive galaxy cluster. We employ high-resolution magnetohydrodynamic cosmological zoom-in simulations to resolve the turbulent motions in the intracluster medium. We find that the tur

APA, Harvard, Vancouver, ISO, and other styles

37

Cline, David B. "Primordial black-hole evaporation and the quark-gluon phase transition." Nuclear Physics A 610 (December 1996): 500–507. http://dx.doi.org/10.1016/s0375-9474(96)00383-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Martin, Adrian P., and Anne-Christine Davis. "The stability of primordial magnetic fields produced by phase transitions." Physics Letters B 360, no. 1-2 (1995): 71–76. http://dx.doi.org/10.1016/0370-2693(95)01120-f.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Papanikolaou, Theodoros, Shreya Banerjee, Yi-Fu Cai, Salvatore Capozziello, and Emmanuel N. Saridakis. "Primordial black holes and induced gravitational waves in non-singular matter bouncing cosmology." Journal of Cosmology and Astroparticle Physics 2024, no. 06 (2024): 066. http://dx.doi.org/10.1088/1475-7516/2024/06/066.

Full text

Abstract:

Abstract We present a novel model-independent generic mechanism for primordial black hole formation within the context of non-singular matter bouncing cosmology. In particular, considering a short transition from the matter contracting phase to the Hot Big Bang expanding Universe, we find naturally enhanced curvature perturbations on very small scales which can collapse and form primordial black holes. Interestingly, the primordial black hole masses that we find can lie within the observationally unconstrained asteroid-mass window, potentially explaining the totality of dark matter. Remarkably

APA, Harvard, Vancouver, ISO, and other styles

40

Choudhury, Sayantan, Ahaskar Karde, Sudhakar Panda, and M. Sami. "Primordial non-Gaussianity from ultra slow-roll Galileon inflation." Journal of Cosmology and Astroparticle Physics 2024, no. 01 (2024): 012. http://dx.doi.org/10.1088/1475-7516/2024/01/012.

Full text

Abstract:

Abstract We present a detailed study of the generation of large primordial non-Gaussianities during the slow-roll (SR) to ultra-slow roll (USR) transitions in the framework of Galileon inflation. We found out that due to having sharp transitions in the USR phase, which persist with a duration of Δ𝒩USR ∼ 2 e-folds, we are able to generate the non-Gaussianity amplitude of the order: |f NL| ∼ 𝒪(10-2) in the SRI, -5 < f NL < 5 in the USR, and -2 < f NL < 2 in the SRII phases. As a result, we are able to achieve a cumulative average value of |f NL| ∼ 𝒪(1). This implies that our results

APA, Harvard, Vancouver, ISO, and other styles

41

Vasconcellos, César A. Zen, Peter O. Hess, José A. de Freitas Pacheco, et al. "Relic Gravitational Waves in the Noncommutative Foliated Riemannian Quantum Gravity." Universe 11, no. 6 (2025): 179. https://doi.org/10.3390/universe11060179.

Full text

Abstract:

We present a study of relic gravitational waves based on a foliated gauge field theory defined over a spacetime endowed with a noncommutative algebraic–geometric structure. As an ontological extension of general relativity—concerning manifolds, metrics, and fiber bundles—the conventional space and time coordinates, typically treated as classical numbers, are replaced by complementary quantum dual fields. Within this framework, consistent with the Bekenstein criterion and the Hawking–Hertog multiverse conception, singularities merge into a helix-like cosmic scale factor that encodes the topolog

APA, Harvard, Vancouver, ISO, and other styles

42

Cheng, Shu-Lin, Da-Shin Lee, and Kin-Wang Ng. "Primordial perturbations from ultra-slow-roll single-field inflation with quantum loop effects." Journal of Cosmology and Astroparticle Physics 2024, no. 03 (2024): 008. http://dx.doi.org/10.1088/1475-7516/2024/03/008.

Full text

Abstract:

Abstract It is known that the single-field inflation with a transient ultra-slow-roll phase can produce a large curvature perturbation at small scales for the formation of primordial black holes. In our previous work, we have considered quantum loop corrections to the curvature perturbation and found that the growth of these small-scale modes would affect the curvature perturbation at large scales probed by cosmic microwave background observation. In this work, we will further derive the constraints on the growing modes in the transition between the slow-roll and the ultra-slow-roll phases und

APA, Harvard, Vancouver, ISO, and other styles

43

Moniruzzaman, M., J. Lee, and T. Miyano. "253 GROWTH OF PRIMORDIAL OOCYTES FROM INFANT AND ADULT PORCINE OVARIES IN XENOGRAFTS." Reproduction, Fertility and Development 19, no. 1 (2007): 243. http://dx.doi.org/10.1071/rdv19n1ab253.

Full text

Abstract:

Mammalian ovaries contain a lot of small oocytes in primordial follicles. A small proportion of these primordial oocytes (oocytes in primordial follicles) start to grow and reach full size, and finally they are ovulated. The mechanism regulating the activation of primordial oocytes to enter the growth phase is not understood yet. This experiment was aimed to compare the growth of primordial oocytes from infant and adult pigs. Ovarian cortical tissues containing primordial follicles collected from infant (10–20-day-old) and adult (6-month-old) pigs were xenografted under the kidney capsules of

APA, Harvard, Vancouver, ISO, and other styles

44

Domènech, Guillem, Gerson Vargas, and Teófilo Vargas. "An exact model for enhancing/suppressing primordial fluctuations." Journal of Cosmology and Astroparticle Physics 2024, no. 03 (2024): 002. http://dx.doi.org/10.1088/1475-7516/2024/03/002.

Full text

Abstract:

Abstract Enhancements of primordial curvature fluctuations in single field inflation often involve departures from attractor trajectories in the phase space. We study enhancement/suppression of primordial fluctuations in one of the simplest models with exact background solutions for arbitrary initial conditions: a single field inflationary model with a piecewise exponential potential. We then present close to exact analytical solutions for primordial fluctuations in a general transition between two slow-roll attractors, valid whether the first slow parameter increases or decreases. The main fe

APA, Harvard, Vancouver, ISO, and other styles

45

Martin-Alvarez, Sergio, Harley Katz, Debora Sijacki, Julien Devriendt, and Adrianne Slyz. "Unravelling the origin of magnetic fields in galaxies." Monthly Notices of the Royal Astronomical Society 504, no. 2 (2021): 2517–34. http://dx.doi.org/10.1093/mnras/stab968.

Full text

Abstract:

ABSTRACT Despite their ubiquity, there are many open questions regarding galactic and cosmic magnetic fields. Specifically, current observational constraints cannot rule out whether magnetic fields observed in galaxies were generated in the early Universe or are of astrophysical nature. Motivated by this, we use our magnetic tracer algorithm to investigate whether the signatures of primordial magnetic fields persist in galaxies throughout cosmic time. We simulate a Milky Way-like galaxy down to z ∼ 2–1 in four scenarios: magnetized solely by primordial magnetic fields, magnetized exclusively b

APA, Harvard, Vancouver, ISO, and other styles

46

Pi, Shi, and Jianing Wang. "Primordial black hole formation in Starobinsky's linear potential model." Journal of Cosmology and Astroparticle Physics 2023, no. 06 (2023): 018. http://dx.doi.org/10.1088/1475-7516/2023/06/018.

Full text

Abstract:

Abstract We study the power spectrum of the comoving curvature perturbation ℛ in the model that glues two linear potentials of different slopes, originally proposed by Starobinsky. We find that the enhanced power spectrum reaches its maximum at the wavenumber which is π times the junction scale. The peak is ∼ 2.61 times larger than the ultraviolet plateau. We also show that its near-peak behavior can be well approximated by a constant-roll model, once we define the effective ultra-slow-roll e-folding number appropriately by considering the contribution from non-single-clock phase only. Such an

APA, Harvard, Vancouver, ISO, and other styles

47

Kumar, N., R. Manikandhan, P. Anantanarayanan, and K. Agarwal. "An Unusual Combination of Primordial Dwarfism with Isolated Cleft Palate." International Journal of Medical and Dental Sciences 1, no. 2 (2012): 20. http://dx.doi.org/10.18311/ijmds/2012/18697.

Full text

Abstract:

Primordial dwarfism is a rare anomaly with over 200 sub-types, which results in a relatively small body size in all stages of life, beginning at the intrauterine period. The life expectancy for these patients is around 30 years but very few survive their intra-uterine phase. Other features associated with primary dwarfism reported till date includes pigmentation of skin, cleft lip and palate, and semilobar holoprosencephaly. We report an unusual combination of primordial dwarfism associated with isolated cleft palate.

APA, Harvard, Vancouver, ISO, and other styles

48

del-Corral, Daniel, Paolo Gondolo, K. Sravan Kumar, and João Marto. "Revisiting primordial black holes formation from preheating instabilities: the case of Starobinsky inflation." Journal of Cosmology and Astroparticle Physics 2025, no. 02 (2025): 009. https://doi.org/10.1088/1475-7516/2025/02/009.

Full text

Abstract:

Abstract In recent years, the formation of primordial black holes (PBH) in the early universe inflationary cosmology has garnered significant attention. One plausible scenario for primordial black hole (PBH) formation arises during the preheating stage following inflation. Notably, this scenario does not necessitate any ad-hoc fine-tuning of the scalar field potential. This paper focuses on the growth of primordial density perturbation and the consequent possibility of PBH formation in the preheating stage of the Starobinsky model for inflation. The typical mechanism for PBH formation during p

APA, Harvard, Vancouver, ISO, and other styles

49

Elmfors, Per, Kari Enqvist, and Kimmo Kainulainen. "Strongly first order electroweak phase transition induced by primordial hypermagnetic fields." Physics Letters B 440, no. 3-4 (1998): 269–74. http://dx.doi.org/10.1016/s0370-2693(98)01117-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Heckler, Andrew F. "Effects of electroweak phase transition dynamics on baryogenesis and primordial nucleosynthesis." Physical Review D 51, no. 2 (1995): 405–28. http://dx.doi.org/10.1103/physrevd.51.405.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!