[set fair (OP)]

I tend to think of the hierarchy of thinking in physics as idea - hypothesis - theory. Current thinking on inflation has come up with the idea that it was caused by an inflationary field and attempts have been made to describe what such a field would be like, its properties, magnitude etc. But it's still just an idea.

I have an alternative although it is only a half baked idea. It stems from the idea that given
virtual particles spontaneously flit in and out of existence at a rate per unit volume per unit time which is governed by the laws of physics then in principle one could calculate the volume of a given bit of space by counting the virtual particles over a measured time. In principle... the fact that they couldn't actually be counted doesn't matter  for what I'm going on to say. What matters here is that if there are more of them, there is more space. In a sense you can think of them as being space... much as you can think of the Euclidean dimensions of a block of space as defining space.

During the inflationary period, the number of virtual particles flitting in and out of existence per unit time in the universe as a whole must have increased dramatically. So I ask the question - where did they come from,

Suppose you meet someone who tells you about a new particle - the improbiblon, which has a mass almost 27 times that of a proton, a charge of minus two and a spin of six and a half. You explain to him that the chances of here being such a particle are nil, but they insist that virtual improboblons do exist. They go on to say that because an actual improbablon doesn't exist, its virtual counterpart can not interact with any real particle and can't be detected. In fact they claim there would be no difference whether or not virtual improbablons exist, so you can't prove they don't. It would also mean that the existence of virtual improbablons would have no effect on the volume of space (otherwise there would be evidence for their existence and they would have an effect on the universe)

From this comes the idea that virtual particles which have no real particle counterpart can exist but they do not count when you calculate the volume of space. ie they are only space if and when their real counterparts exist.

So back to the moment before inflation began. The first particle in the standard model is born and with it, all at once its virtual particles now need to be counted as space. This manifests as an abrupt increase in the volume of the universe. Consequently the number of virtual particles of the other particles of the standard model increase - at this stage their real counterparts don't exist, so they don't count as space - there are just more of them per unit time than there were before the first particle caused the expansion. Then the process repeats as each of the particles of the standard model come into existence. Taken together, this is inflation and it comes to a halt as abruptly as it started when the last particle of the standard model comes into existence.

[alancalverd]

the number of virtual particles flitting in and out of existence per unit time in the universe as a whole must have increased dramatically. So I ask the question - where did they come from,

The nice thing about virtual particles is that if they are truly complementary, they don't need to come from or go to anywhere. Every VP has its antiVP,  so there is no net anything.

Which makes the universe either inevitable or vanishingly improbable. From where I sit, it looks temporarily inevitable.

[Zer0]

@set fair

As the Universe expands, do the Amounts of VPs also Increase?

Say, if i blow a baloon.
As it's Size increases, air molecules count within it increases too.

ps - i know the air was pulled in from my environment & now is residual coming outta my lungs, but what bout VPs, where do They come from?

[paul cotter]

"What caused inflation?" Bad monetary policy obviously (sorry!!)

[Eternal Student]

Hi.

    We may need to take some care when developing a model with virtual particles.  You've taken a notion that is far from certain and was originally intended only to serve as a picture to simplify explanations and then you've run as far as you can with that illustration.
    When PopSci articles describe things they do tend to use phrases like "virtual particles" because it's easier for most people to imagine something in terms of particles doing something.    "Virtual particles" may be nothing more than a metaphor, simplified model or just an illustration of an idea.    In much the same way that gravity isn't a rubber sheet that gets stretched when a planet rests on top of it even though this representation is shown in many diagrams, virtual particles are just something happening in quantum fields.    It can be helpful to imagine interactions as an exchange of virtual particles but most experts stop short of declaring that virtual particles would actually be exactly like some sort of real particle.

The first thing you need to know is that virtual particles ...  ...aren't really particles at all.  The language makes people misunderstand 
   2nd paragraph,  New Scientist,  Why virtual particles don't exist but do explain reality,   https://www.newscientist.com/article/mg25834383-000-why-virtual-particles-dont-exist-but-do-explain-reality-for-now/

The term (virtual particle) is somewhat loose and vaguely defined....   ....The accuracy and use of virtual particles in calculations is firmly established, but as they cannot be detected in experiments, deciding how to precisely describe them is a topic of debate.
     Wikipedia.    https://en.wikipedia.org/wiki/Virtual_particle

Best Wishes.

[Zer0]

The term (virtual particle) is somewhat loose and vaguely defined....   ....The accuracy and use of virtual particles in calculations is firmly established, but as they cannot be detected in experiments, deciding how to precisely describe them is a topic of debate.
     Wikipedia.    https://en.wikipedia.org/wiki/Virtual_particle

Best Wishes.

A likely follow-up question that pops in a layman's Mind is...
Then what about dark Matter & dark Energy?

Could both of em, Simply be two sides of the same Coin, known as Gravity!