What is the monopole problem?
The Monopole Problem: Inflation allows for magnetic monopoles to exist as long as they were produced prior to the period of inflation. During inflation, the density of monopoles drops exponentially, so their abundance drops to undetectable levels.
What is the horizon problem in cosmology?
CMB regions that are separated by more than 2° lie outside one another’s particle horizons and are causally disconnected. The horizon problem describes the fact that we see isotropy in the CMB temperature across the entire sky, despite the entire sky not being in causal contact to establish thermal equilibrium.
Are black holes monopoles?
The pair’s calculations have revealed that black holes might be harbouring enigmatic hypothetical entities called magnetic monopoles. Dirac proposed that monopoles are necessary to explain why electrons carry just a single electric charge, and why all other charged particles carry multiples of this charge.
Does monopole exist?
As implied by its name, the magnetic monopole consists of a single pole, as opposed to the dipole, which is comprised of two magnetic poles. As yet there is no evidence for the existence of magnetic monopoles, but they are interesting theoretically.
How do I contact Alan Guth?
Contact Information
- office:617-253-6265.
- [email protected].
- Physics Faculty Page.
Where did Alan Guth go to school?
Massachusetts Institute of Technology1971
Massachusetts Institute of TechnologyHighland Park High School
Alan Guth/Education
What are the horizon and flatness problems?
The small universe inflated by a large amount and the part of the universe you can observe appears to be nearly flat. That solves the flatness problem. The horizon problem is solved by inflation because regions that appear to be isolated from each other were in contact with each other before the inflation period.
Why does the universe have a horizon?
A cosmological horizon is a measure of the distance from which one could possibly retrieve information. This observable constraint is due to various properties of general relativity, the expanding universe, and the physics of Big Bang cosmology. Cosmological horizons set the size and scale of the observable universe.
How does a monopole antenna work?
The monopole is often used as a resonant antenna; the rod functions as an open resonator for radio waves, oscillating with standing waves of voltage and current along its length. Therefore the length of the antenna is determined by the wavelength of the radio waves it is used with.
Is the flatness problem a cosmological problem?
The flatness problem (also known as the oldness problem) is a cosmological fine-tuning problem within the Big Bang model of the universe. Such problems arise from the observation that some of the initial conditions of the universe appear to be fine-tuned to very ‘special’ values, and that small deviations from these values…
Is the monopole term of a magnetic field always zero?
However, in the multipole expansion of a magnetic field, the “monopole” term is always exactly zero (for ordinary matter). A magnetic monopole, if it exists, would have the defining property of producing a magnetic field whose monopole term is non-zero.
Is the magnetic monopole related to condensed matter?
Since 2009, numerous news reports from the popular media have incorrectly described these systems as the long-awaited discovery of the magnetic monopoles, but the two phenomena are only superficially related to one another. These condensed-matter systems remain an area of active research. (See § “Monopoles” in condensed-matter systems below.)
How does inflation affect the standard model of cosmology?
Observational status. Inflation is a mechanism for realizing the cosmological principle, which is the basis of the standard model of physical cosmology: it accounts for the homogeneity and isotropy of the observable universe. In addition, it accounts for the observed flatness and absence of magnetic monopoles.