scholarly journals Hydrogen spin oscillations in a background of axions and the 21-cm brightness temperature

2020 ◽  
Author(s):  
G Lambiase ◽  
S Mohanty
Keyword(s):  
Cosmic Strings ◽  
Transition Rates ◽  
Spin Temperature ◽  
Level Atom ◽  
Spin Flip ◽  
Coherent Field ◽  
Unique Method ◽  
Photon Process ◽  
The Right ◽  
The Universe

Abstract The 21-cm line signal arising from the hyperfine interaction in hydrogen has an important role in cosmology and provides a unique method for probing of the universe prior to the star formation era. We propose that the spin flip of Hydrogen by the coherent emission/absorption of axions causes a lowering of their spin temperature and can explain the stronger than expected absorption of 21-cm light reported by the EDGES collaboration. We find the analogy of axion interaction with the two level HI with the Jaynes-Cummings model of a two level atom in a cavity and we derive the spin flip frequency in this formalism and show that the coherent oscillations frequency Ω∝1/fa in contrast with the incoherent transitions between the HI hyperfine levels where the transition rates $\propto 1/f_a^2$. The axion emission and absorption rates are equal but the spin temperature is still lowered due to different selection rules for the spin flip transitions compared to the photon process. We show that the axion process goes in the right direction for explaining the EDGES observation. For this mechanism to work we require a coherent field of relativistic axions with energy Eν peaked at the 21-cm spin-flip energy. Such a coherent background of relativistic axions can arise from the decay of cosmic strings if the decay takes place in the electroweak era.

ENTANGLEMENT FOR JAYNES CUMMINGS MODEL IN THE PRESENCE MULTI-PHOTON PROCESS UNDER DECOHERENCE EFFECT

2013 ◽  
Vol 11 (03) ◽  
pp. 1350026 ◽  
Author(s):  
S. ABDEL-KHALEK ◽  
M. S. ALMALKI
Keyword(s):  
Quantum Computer ◽  
Single Mode ◽  
Entanglement Dynamics ◽  
Nonlocal Correlation ◽  
Phase Damping ◽  
Level Atom ◽  
Coherent Field ◽  
Photon Process ◽  
Quantized Field ◽  
Decoherence Effect

The quantum nonlocal correlation between an atom and coherent field is described quantitatively in terms of multi-photon and phase damping processes. Especially, considering a two-level atom interacts with a single-mode quantized field in a coherent state inside a phase-damped cavity, and taking into account the number of multi-photon transitions and phase damping effect, the entanglement is investigated during the time evolution as a function of involved' parameters in the system. The results show that the enhancement of the transitions are very useful in generating a high amount of entanglement. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement dynamics between the bipartite system with its environment is evaluated and investigated during the dissipative process. Finally, the physical interpretation of the correlation behaviors between the subsystems is explained through the statistical properties of the field.

scholarly journals Primordial monopoles and strings, inflation, and gravity waves

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Joydeep Chakrabortty ◽  
George Lazarides ◽  
Rinku Maji ◽  
Qaisar Shafi
Keyword(s):  
Symmetry Breaking ◽  
Gravity Waves ◽  
Cosmic Strings ◽  
Wave Spectrum ◽  
Gauge Coupling ◽  
String Tension ◽  
Magnetic Monopoles ◽  
Intermediate Scale ◽  
Tension Parameter ◽  
The Universe

Abstract We consider magnetic monopoles and strings that appear in non-supersymmetric SO(10) and E6 grand unified models paying attention to gauge coupling unification and proton decay in a variety of symmetry breaking schemes. The dimensionless string tension parameter Gμ spans the range 10−6− 10−30, where G is Newton’s constant and μ is the string tension. We show how intermediate scale monopoles with mass ∼ 1013− 1014 GeV and flux ≲ 2.8 × 10−16 cm−2s−1sr−1, and cosmic strings with Gμ ∼ 10−11− 10−10 survive inflation and are present in the universe at an observable level. We estimate the gravity wave spectrum emitted from cosmic strings taking into account inflation driven by a Coleman-Weinberg potential. The tensor-to-scalar ratio r lies between 0.06 and 0.003 depending on the details of the inflationary scenario.

scholarly journals KOSMOLOGI RUANG VERTIKAL DAN HORIZONTAL PADA RUMAH TRADISIONAL (SA’O) DESA ADAT SAGA, KABUPATEN ENDE, FLORES

2017 ◽  
Vol 1 (2) ◽  
pp. 171
Author(s):  
Zulkifli H. Achmad ◽  
Antariksa Sudikno ◽  
Agung Murti Nugroho
Keyword(s):  
Human Life ◽  
Body Parts ◽  
The Core ◽  
Ethnographic Approach ◽  
Humanitarian Space ◽  
Human World ◽  
Home Space ◽  
The Right ◽  
The Relationship ◽  
The Universe

Title: Vertical and Horizontal Room Cosmology in Traditional House (Sa’o) Adat Saga Village, Ende Regency, Flores Cosmology is the science related to kemestaan (cosmos) in a concept of the relationship between the human world (micro-cosmos) and of the universe. Space in traditional house Saga has values and khasan interesting architecturally is examined. The influence of Ngga'e on the Du'a belief and traditional home space Saga interesting architecturally is identified. This study uses qualitative methods with an ethnographic approach that is description. The findings of this study is about the cosmology of the space on a traditional home. Cosmological view of space in traditional house Saga is distinguished into three parts namely is lewu, gara as one and mention the position of the human body parts. Cosmological view of space in traditional Indigenous Villages (Sa'o) Saga depicted horizontally with the mother lay. Nature of traditional house Saga is the core of fertility and birth. Being a mother is clearly visible on a carved door (pene ria) enter Sa'o believe carving the breasts of a woman who symbolizes the human life and a transverse under IE peneria koba leke symbolizing the human development. The position of the head of the mother at the lulu (the dugout), second legs on his back is to the fore in the tent (dugout or accepting guests), second hand mereba is at the right and left dhembi space, the womb or humanitarian space are at puse ndawa. Keywords: traditional house (sa'o), the indigenous village of saga, the cosmology of the vertical and horizontal spaces

Theory and Modelling

2017 ◽  
pp. 1-19
Keyword(s):  
Complex System ◽  
Economic Model ◽  
Fractal Structure ◽  
Explanatory Role ◽  
Neoclassical Theory ◽  
Equilibrium Dynamics ◽  
The Right ◽  
Formal Properties ◽  
The Universe

In this chapter, I discuss the dominance of the neoclassical theory. The effort here is to highlight the importance of studying economics as an adaptive complex system where the fractal structure and interaction play a fundamental explanatory role and individual details are largely relevant. To discard equilibrium in the standard sense and to move on to study out of equilibrium dynamics is surely the right way to proceed but is perhaps too big a step for economics at this time. Inspired of the Newton's model of the universe, economists developed an economic model that had the same formal properties. So, once economics and finance made it their goal to develop the concept and the idea of the elegant model form, they go along with the simplified assumptions of that form. Therefore, financial models can leave us unable to see many of the most important aspects of financial markets.

Seneca on Comets and Ancient Cometary Theory in Natural Questions 7

Ramus ◽  
2007 ◽  
Vol 36 (2) ◽  
pp. 97-117 ◽  
Author(s):  
Gareth Williams
Keyword(s):  
The Right ◽  
The Mind ◽  
Mind's Eye ◽  
The Universe ◽  
Insight Into

Seneca's focus on comets inNatural Questions7 concentrates our attention on a phenomenon that is in a sense familiar but so distant, known but so unknown; they are obscurities that ‘both fill and escape our eyes’ (7.30.4), and which challenge us to project the mind's eye beyond the limits of our ordinary vision as we seek insight into nature's mysteries. The broad aim of this paper is to argue that Seneca's treatment of comets shapes, and actively applies in inventive ways within the text, a mindset that moves restlessly from narrow, more ‘terrestrial’ ways of reflecting upon the universe towards an unfettered mode of investigation that looks daringly beyond the limits of the visible and known to speculate on what lies beyond. This mindset proceeds by conjecture and ‘neither with any assurance of finding [the truth] nor without hope’ (7.29.3), but it nevertheless follows the ‘right’ (Senecan) path even in possible error: it reaches dynamically beyond conventional confines—in this case, the zodiac—to engage with the universal immensity in ways that aspire to that main Senecan goal in theNatural Questionsas whole, ‘to see the all with the mind’ (cf.animo omne uidisse, 3 pref. 10).

FIELD PURIFICATION OF A GENERAL THREE-LEVEL SYSTEM INTERACTING WITH RADIATION

2003 ◽  
Vol 17 (07) ◽  
pp. 253-262 ◽  
Author(s):  
MAHMOUD ABDEL-ATY
Keyword(s):  
Exact Solution ◽  
Electromagnetic Field ◽  
Density Operator ◽  
Photon Number ◽  
Entangled State ◽  
Level System ◽  
Level Atom ◽  
Coherent Field ◽  
Field Purity ◽  
Intensity Dependent Coupling

In this essay we introduce a new Hamiltonian which represents the interaction between a three-level atom and a single electromagnetic field including arbitrary forms of nonlinearities of both the field and the intensity-dependent coupling. We derive an exact solution for the density operator of the system by means of which we study the field purity for the entangled state of the system. Also, the influences of the nonlinearities on the field purity and mean photon number are examined. Under the condition of an initial coherent field, the field purity shows the collapse-revival phenomenon. It is found that features of these phenomenon are sensitive to the changes of different kinds of the nonlinearities.

scholarly journals Phase Transitions and Topological Defects in the Early Universe

1997 ◽  
Vol 50 (4) ◽  
pp. 697 ◽  
Author(s):  
T. W. B. Kibble
Keyword(s):  
Phase Transitions ◽  
Low Temperature ◽  
Early Universe ◽  
Particle Physics ◽  
Defect Density ◽  
Cosmic Strings ◽  
Condensed Matter ◽  
Topological Defects ◽  
Helium 3 ◽  
The Universe

Our present theories of particle physics and cosmology, taken together, suggest that very early in its history, the universe underwent a series of phase transitions, at which topological defects, similar to those formed in some condensed matter transitions, may have been created. Such defects, in particular cosmic strings, may survive long enough to have important observable effects in the universe today. Predicting these effects requires us to estimate the initial defect density and the way that defects subsequently evolve. Very similar problems arise in condensed matter systems, and recently it has been possible to test some of our ideas about the formation of defects using experiments with liquid helium-3 (in collaboration with the Low Temperature Laboratory in Helsinki). I shall review the present status of this theory.

Islamic Modernism: Its Scope, Method and Alternatives

1970 ◽  
Vol 1 (4) ◽  
pp. 317-333 ◽  
Author(s):  
Fazlur Rahman
Keyword(s):  
Nineteenth Century ◽  
The West ◽  
Modern Education ◽  
Islamic Reform ◽  
The Status ◽  
Spiritual Issues ◽  
The Right ◽  
Law Of Evidence ◽  
The Universe ◽  
Status Of Women

The classical Muslim modernists of the nineteenth century envisaged Islamic Reform as a comprehensive venture: it took in its purview law, society, politics and intellectual, moral and spiritual issues. It dealt with questions of the law of evidence, the status of women, modern education, constitutional reforms, the right of a Muslim to think for himself, God and the nature of the universe and man and man's freedom. A tremendous intellectual fervour and ferment were generated. The liberals and the conservatives battled; the intellectual innovators were opposed and supported, penalized and honored, exiled and enthusiastically followed. Although the modernist movement dealt with all the facets of life, nevertheless, in my view, what gave it point and significance was its basically intellectual élan and the specifically intellectual and spiritual issues with which it dealt. This awakening struck a new and powerful chord in the Muslim mind because intellectual issues had remained for centuries under a state of selfimposed dormancy and stagnation at the instance of conservative orthodoxy. The nineteenth century was also the great age of the battle of ideas in the West, ideas and battles whose strong injections into Muslim society found a ready response. The character of this movement was then primarily intellectual and spiritual.

TWO-LEVEL ATOM UNDERGOING TWO PHOTON TRANSITION IN A QUANTIZED FIELD: THE FLUORESCENT SPECTRUM

1992 ◽  
Vol 06 (12) ◽  
pp. 729-736
Author(s):  
AMITABH JOSHI ◽  
S. V. LAWANDE
Keyword(s):  
Fluorescence Spectrum ◽  
Two Photon ◽  
Photon Transition ◽  
Dressed States ◽  
Level Atom ◽  
Coherent Field ◽  
Fluorescent Spectrum ◽  
Qualitative Nature ◽  
Quantized Field ◽  
The Mean

The fluorescence spectrum produced by a two-photon Jaynes-Cummings model (JCM) has been analyzed using the infinity of transitions among the dressed states of its Hamiltonian. A large number of resonances in the spectra are observed which are sensitive to the mean photon numbers of the quantized coherent field. Also, the qualitative nature of these spectra are in contrast to that of the corresponding spectra of standard JCM.

‘Cambridge Idealism’: Utilitarian Revisionists in Late Nineteenth-Century Cambridge

1974 ◽  
Vol 17 (1) ◽  
pp. 63-78 ◽  
Author(s):  
C. J. Dewey
Keyword(s):  
Nineteenth Century ◽  
Social Problems ◽  
Late Nineteenth Century ◽  
Late Nineteenth ◽  
The Right ◽  
Secular Religion ◽  
The Universe

‘Cambridge idealism’ – the phrase sounds like a mischievous verbal paradox. Idealism, as Richter has accustomed us to suppose, set the tone of late nineteenth-century Oxford; while contemporary Cambridge, Lord Annan teaches, preserved a tradition of empirical rationalism. At Balliol Green and Toynbee evolved a ‘secular religion’ from the metaphysics of Hegel and Kant; at Cambridge Sidgwick and Marshall embarked upon a rationalist revision of utilitarianism, developing (for the most part) suggestions incompletely worked out by Mill. Green and Toynbee were idealists; Sidgwick and Marshall were rationalists: the differences between the philosophic systems thery constructed seem crystal clear. Yet the contrast can be exaggerated. Whether their fundamental premiss was the principle of utility or the conviction that ‘the Universe is a single, eternal activity or energy, of which it is the essence to be self-conscious, that is, to be itself and not-itself,’ Oxford idealists and Cambridge rationalists were both preoccupied by contemporary social problems, both formulated essentially social philosophies concerned with the right conduct of individuals in their relations with others, and both arrived at comparable policy prescriptions at almost exactly the same time.

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