What was the role of Hawking Radiation in the early universe?

[big_bounce]

Amount of Planck energy is 1.956 * 10^9 J.
Was this total energy of universe at plank time at big bang cosmology model?
It's clear this amount of energy is not enough for making our solar system, even it's not enough for making mass of me ( 60 kg ).
Should we postulate energy increase in the universe after Planck time?

If yes, how could? by means quantum tunneling? inflation?

 

[Drakkith]

Amount of Planck energy is 1.956 * 10^9 J.
Is this total energy of universe at plank time at big bang cosmology model?

No, it's just the unit of energy you get when you set the constants G, ћ and c to 1.
https://en.wikipedia.org/wiki/Planck_energy

 

[big_bounce]

No, it's just the unit of energy you get when you set the constants G, ћ and c to 1.
https://en.wikipedia.org/wiki/Planck_energy

Temperature of universe at Planck time was 10^32 K.
http://www.uni.edu/morgans/astro/course/Notes/section3/bigbang.html
If mass of universe was more than Planck mass, the temperature of universe couldn't be 10^32 K.
Planck mass times c square gives us Planck energy.

 

[Drakkith]

If mass of universe was more than Planck mass, the temperature of universe couldn't be 10^32 K.

Why not?

 

[big_bounce]

Why not?

Because c and k are constant in this formula.

 

[Chronos]

How does that compare to the Planck temperature? A leading question, I admit.

 

[Drakkith]

Because c and k are constant in this formula.

And how does that tell us that the mass of the universe at Planck time couldn't be more than the Planck mass?

 

[big_bounce]

And how does that tell us that the mass of the universe at Planck time couldn't be more than the Planck mass?

If i put my mass (60 kg) at this formula we don't get 10³²K.

 

[big_bounce]

How does that compare to the Planck temperature? A leading question, I admit.

Read here:
At the plank time the radius of universe is the plank length of 1.6 * 10^-35 and the Planck temprature is 10³²K.
https://books.google.com/books?id=K...ed=0ahUKEwjyldvW49PKAhXE2SwKHTaSCTk4FBDoAQgeM

 

[Drakkith]

If i put my mass (60 kg) at this formula we don't get 10³²K.

Of course you don't. That's not how you use the equation. Unfortunately you'll have to look into how temperature is defined in order to see why the equation is set up the way it is (or wait for someone with more knowledge than myself to explain it).

 

[PeterDonis]

If i put my mass (60 kg) at this formula we don't get 10³² K.

Temperature is not the total energy; it's the average energy per particle. If you have 60 kg worth of particles each one of which has the Planck energy, then the temperature of the whole system is the Planck temperature.

 

[bcrowell]

Was this total energy of universe at plank time at big bang cosmology model?

There is no way to define the total energy of the universe. We have a FAQ about this:
https://www.physicsforums.com/threads/what-is-the-total-mass-energy-of-the-universe.506985/

 

[newjerseyrunner]

My understanding of the early universe is that most of the energy of the universe was created by Hawking Radiation during inflation, not the instant of creation.

 

[bcrowell]

My understanding of the early universe is that most of the energy of the universe was created by Hawking Radiation during inflation, not the instant of creation.

This sounds wrong to me for a variety of reasons. Energy is locally (but not globally) conserved, so we don't have processes that create energy. There is no "instant of creation," since GR doesn't describe a singularity as a point on the spacetime manifold.

 

[PeterDonis]

My understanding of the early universe is that most of the energy of the universe was created by Hawking Radiation during inflation

No, this is not correct, for at least two reasons. First, what happened at the end of inflation was not "creation of energy"; it was just a transfer of energy from the inflaton field to the fields described by the Standard Model of particle physics (quarks, electrons, neutrinos, etc.), caused by the inflaton field changing state from the "false vacuum" state it had during inflation, to the "true vacuum" state it has had ever since. Second, this energy transfer process (which is called "reheating" in cosmology, something of a misnomer since there was no previous "heating" of anything) was not Hawking radiation and bears no resemblance to it.