Recent Developments in Cosmology
... From our vantage point 13 billion years after the Big Bang, we are now trying to unravel what happened in the earliest tiny fraction of a second, when the Universe was 0.000000000000000000000000000000000001 seconds old! We can test our ideas about the Very Early Universe by observing the distributio ...
... From our vantage point 13 billion years after the Big Bang, we are now trying to unravel what happened in the earliest tiny fraction of a second, when the Universe was 0.000000000000000000000000000000000001 seconds old! We can test our ideas about the Very Early Universe by observing the distributio ...
Mass Outflow in the Seyfert 1 Galaxy NGC 4151
... • Neutrinos (not enough of them); also, can’t account for galaxy formation (too “hot”) • MACHOs – massive compact halo objects; should act as gravitational lenses – a few detected, but not enough ...
... • Neutrinos (not enough of them); also, can’t account for galaxy formation (too “hot”) • MACHOs – massive compact halo objects; should act as gravitational lenses – a few detected, but not enough ...
HST04-Cosmology - Indico
... For conventional matter content |Ω – 1| ~ t|n| , which increases in time, so universe must have been extremely close to the flat geometry at very early times ...
... For conventional matter content |Ω – 1| ~ t|n| , which increases in time, so universe must have been extremely close to the flat geometry at very early times ...
Classical Probability, Shakespearean Sonnets, and
... universe has 1080 baryons with maximum entropy in a big crunch of 1043 photons per baryon while the entropy of the early universe was less than 108 photons per baryon. And in this case, the universe is roughly 14 billion years old while there are roughly 1011 galaxies while each galaxy averages 1011 ...
... universe has 1080 baryons with maximum entropy in a big crunch of 1043 photons per baryon while the entropy of the early universe was less than 108 photons per baryon. And in this case, the universe is roughly 14 billion years old while there are roughly 1011 galaxies while each galaxy averages 1011 ...
The Early Universe and the Big Bang
... because of the curvature of space, very distant regions are actually the same point the big bang started in one place so everything was initially at the same temperature they were originally close together but then a superfast expansion carried them far apart ...
... because of the curvature of space, very distant regions are actually the same point the big bang started in one place so everything was initially at the same temperature they were originally close together but then a superfast expansion carried them far apart ...
Cosmology * The Origin and Evolution of the Universe
... • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond the horizon are unobservable, not just due to limited technology, but even in principle, so it’s not meaningful to talk about their “ ...
... • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond the horizon are unobservable, not just due to limited technology, but even in principle, so it’s not meaningful to talk about their “ ...
Cosmology – The Origin and Evolution of the Universe
... But Wait! (you say…) • That means that the stuff out beyond the horizon must be moving away from us FASTER than the speed of light! • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond ...
... But Wait! (you say…) • That means that the stuff out beyond the horizon must be moving away from us FASTER than the speed of light! • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond ...
Paradigm Shifts in Cosmology
... force so that its effect on the expansion rate is only deceleration. In order to accelerate the expansion, a sort of repulsive force, namely, something that exerts anti-gravity is needed. What we can readily think of is Einstein s cosmological constant. The vacuum energy that caused inflation is al ...
... force so that its effect on the expansion rate is only deceleration. In order to accelerate the expansion, a sort of repulsive force, namely, something that exerts anti-gravity is needed. What we can readily think of is Einstein s cosmological constant. The vacuum energy that caused inflation is al ...
The Big Bang Theory:
... 100,000 years old (horizon is 100,000 light years in diameter) differed from the other side of the sky by 10 million light years - 100 times the diameter of the horizon. How is this possible? ...
... 100,000 years old (horizon is 100,000 light years in diameter) differed from the other side of the sky by 10 million light years - 100 times the diameter of the horizon. How is this possible? ...
How will the universe end?
... may quantum-tunnel into solid iron – it may either evaporate or quantum-tunnel into bhs which radiate away within 10^100000000000000000000000000 years particle density will go to zero – each particle will be cut off from the rest by a cosmological horizon – no interaction possible anymore A. Loeb: h ...
... may quantum-tunnel into solid iron – it may either evaporate or quantum-tunnel into bhs which radiate away within 10^100000000000000000000000000 years particle density will go to zero – each particle will be cut off from the rest by a cosmological horizon – no interaction possible anymore A. Loeb: h ...
Cosmology – The Origin and Evolution of the Universe
... speed of light! • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond the horizon are unobservable, even in principle, so it’s not meaningful to talk about their “velocity relative to us” ...
... speed of light! • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond the horizon are unobservable, even in principle, so it’s not meaningful to talk about their “velocity relative to us” ...
Cosmology – The Origin and Evolution of the Universe
... But Wait! (you say…) • That means that the stuff out beyond the horizon must be moving away from us FASTER than the speed of light! • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond ...
... But Wait! (you say…) • That means that the stuff out beyond the horizon must be moving away from us FASTER than the speed of light! • In a way – yes. But space itself does not have such speed limits. Only matter within space. Space is expanding, carrying the galaxies with it. These galaxies beyond ...
Origin of classical structure from inflation
... formula S = −Tr(ρ ln ρ), where ρ is the reduced density matrix, and use is being made of explicit formulae derived in [14]. The derivation confirms the expectation that the entropy is roughly given by the logarithm of the ellipse in phase space, whose minor axis approaches a finite value due to deco ...
... formula S = −Tr(ρ ln ρ), where ρ is the reduced density matrix, and use is being made of explicit formulae derived in [14]. The derivation confirms the expectation that the entropy is roughly given by the logarithm of the ellipse in phase space, whose minor axis approaches a finite value due to deco ...
Announcements Homework. Final Exam. Isotropy of the CMB
... Background is nearly smooth • < 0.5% density variations when universe was 300,000 yrs old. ...
... Background is nearly smooth • < 0.5% density variations when universe was 300,000 yrs old. ...
June 2015
... I mention that I have never worked on “inflation”. However, I would like to emphasize that I wrote this section on this topic not common for me and under a very great time pressure only because I wanted to show that my perspective could be applied to any great problem regarding the “universe”/”world ...
... I mention that I have never worked on “inflation”. However, I would like to emphasize that I wrote this section on this topic not common for me and under a very great time pressure only because I wanted to show that my perspective could be applied to any great problem regarding the “universe”/”world ...
Big Bang
... We can compare the structures we see in detailed observations of the microwave background with predictions for the “seeds” that should have been planted by inflation So far, our observations of the universe agree very well with models in which inflation planted the “seeds” for future gravitational c ...
... We can compare the structures we see in detailed observations of the microwave background with predictions for the “seeds” that should have been planted by inflation So far, our observations of the universe agree very well with models in which inflation planted the “seeds” for future gravitational c ...
Document
... with stationary stars. If finely balanced, it remains stationary. A single star out of place results in collapse. ...
... with stationary stars. If finely balanced, it remains stationary. A single star out of place results in collapse. ...
Lecture 9
... with stationary stars. If finely balanced, it remains stationary. A single star out of place results in collapse. ...
... with stationary stars. If finely balanced, it remains stationary. A single star out of place results in collapse. ...
From B-Modes to Quantum Gravity and Unification of Forces∗
... Thus recent BICEP2 observations of polarization in the cosmic microwave background will, if confirmed, provide firm empirical evidence for the quantization of gravity. Their details also support quantitative ideas concerning the unification of strong, electromagnetic, and weak forces, and of all the ...
... Thus recent BICEP2 observations of polarization in the cosmic microwave background will, if confirmed, provide firm empirical evidence for the quantization of gravity. Their details also support quantitative ideas concerning the unification of strong, electromagnetic, and weak forces, and of all the ...
Topics in Galaxy Formation
... In many ways, the story of inflation up to this point has been remarkably physics-free. All that has been stated is that an early period of rapid exponential expansion can overcome a number of the fundamental problems of cosmology. The next step involves real physics, but it is not the type of physi ...
... In many ways, the story of inflation up to this point has been remarkably physics-free. All that has been stated is that an early period of rapid exponential expansion can overcome a number of the fundamental problems of cosmology. The next step involves real physics, but it is not the type of physi ...
chapter23 - Montgomery College
... evidence for the Big Bang? – If the universe were eternal, unchanging, and everywhere the same, the entire night sky would be covered with stars – The night sky is dark because we can see back to a time when there were no stars ...
... evidence for the Big Bang? – If the universe were eternal, unchanging, and everywhere the same, the entire night sky would be covered with stars – The night sky is dark because we can see back to a time when there were no stars ...
Lecture 24 Early Universe - University of Maryland
... evidence for the Big Bang? – If the universe were eternal, unchanging, and everywhere the same, the entire night sky would be covered with stars – The night sky is dark because we can see back to a time when there were no stars ...
... evidence for the Big Bang? – If the universe were eternal, unchanging, and everywhere the same, the entire night sky would be covered with stars – The night sky is dark because we can see back to a time when there were no stars ...
Why there is Something rather than Nothing (from
... boson could serve as the inflaton for a scenario with ns» 0.93 and T/S» 0.0004 The mechanism is very different from F.Bezrukov and M.Shaposhnikov, Phys.Lett. 659B (2008) 703 because it is dominated by the quantum effects: CMB data probe quantum anomalous scaling induced by all heavy massive particle ...
... boson could serve as the inflaton for a scenario with ns» 0.93 and T/S» 0.0004 The mechanism is very different from F.Bezrukov and M.Shaposhnikov, Phys.Lett. 659B (2008) 703 because it is dominated by the quantum effects: CMB data probe quantum anomalous scaling induced by all heavy massive particle ...
Inflation (cosmology)
In physical cosmology, cosmic inflation, cosmological inflation, or just inflation is the exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the Big Bang to sometime between 10−33 and 10−32 seconds. Following the inflationary period, the Universe continues to expand, but at a less rapid rate.The inflationary hypothesis was developed in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe (see galaxy formation and evolution and structure formation). Many physicists also believe that inflation explains why the Universe appears to be the same in all directions (isotropic), why the cosmic microwave background radiation is distributed evenly, why the Universe is flat, and why no magnetic monopoles have been observed.While the detailed particle physics mechanism responsible for inflation is not known, the basic picture makes a number of predictions that have been confirmed by observation. The hypothetical field thought to be responsible for inflation is called the inflaton.In 2002, three of the original architects of the theory were recognized for their major contributions; physicists Alan Guth of M.I.T., Andrei Linde of Stanford and Paul Steinhardt of Princeton shared the prestigious Dirac Prize ""for development of the concept of inflation in cosmology"".