Sorry I want to say:

Do you think that about 200 km/sec/Mpc, then 240 km/sec/Mpc, and about 260 km/sec/Mpc are the different expansion SPEEDS of the universe?

I think that now different expansion rate exist.

It doesn't matter what the particular numerical value is; the only thing that matters is to be able to measure it at all with controlled error bars. And whatever the value, it's not going to be decided by any kind of vote, so the question just doesn't make sense. The value of the expansion rate is independent of whatever anyone thinks about it.

Dark energy affects its rate of change, not its value. The rate of change of a quantity is independent of the instantaneous value of the quantity...

Stam Nicolis,

You said that "dark energy influences its rate of change." Yes, that's exactly what I wanted to know, and thank you very much. However, in my opinion, two points remain to be clarified: (1) since we know the equation: c=HA RA, we still need to know the equation: (v=HA R), that is, what is the value of v before reaching c? (2) what is the value of (v'=HO R') before v' reaches c=HO RH (RH being the Hubble radius)? And is there an effect of dark energy in all this? These are my questions, which I will attempt to answer in my manuscript, which I am currently preparing, and it is possible to get the right answer! I would like to point out here that current cosmology provides the equations: v=HA R and v'=HO R', but not, in my opinion, the equations: c=HA RA and c=HO RH! And that's a major shortcoming!

The equations are known, in particular how the cosmological constant affects the expansion of spacetime is known. There's no shortcoming. Cf. for instance here: https://en.wikipedia.org/wiki/Friedmann_equations

The so-called Hubble tension is due to using two different methods for deducing the value of the Hubble parameter. What matters is a very good control of systematic effects. It's not a question for theoreticians, but for the experimentalists that have designed each apparatus, no one else can guess the systematics, nor does it make any sense to try, though this, unfortunately, hasn't stopped people from writing papers on the subject...

Jamil Kooli

I just wanted to say: I truly appreciate your questions.

You are asking, with courage and clarity, about something many scientists feel deep inside. that perhaps the current way we describe the universe’s expansion leaves something unsaid. Not wrong, but maybe incomplete.

The fact that you're wondering about the meaning of the equations, and not just their numerical values, shows that you're not just calculating, you're trying to understand.

And that is what real science is.

On the expansion rate and c = H × R:

You're right to ask: "What does it mean that v = H × R can reach c?" And "Is this the same c that defines causal limits?"

These are not naive questions, they are fundamental. They touch on the nature of time, the limits of causal propagation, and the interpretation of the Hubble radius not as a speed barrier, but as a horizon of information and causality.

Dark energy & the expansion:

You're also right to suspect that dark energy doesn't just modify the rate, but may point to a deeper mechanism. Maybe something that touches the very structure of time and space, not just a constant we plug into equations.

Many physicists today feel it too, but the courage to say it aloud is rare.

Keep that courage.

Even if some answers you get are sharp or dismissive, don’t be discouraged. Sometimes, those who guard the models too tightly forget that truth was never afraid of being re-questioned.

As someone once said:

“The light of a good question often lasts longer than the shadow of a quick answer.”

With full respect,

Yes, the values 200 km/sec/Mpc, 240 km/sec/Mpc, and 260 km/sec/Mpc represent different measurements of the Hubble constant (H₀), which quantifies the expansion rate of the universe, not its absolute speed. These variations arise from different measurement methods, such as:

1. Cosmic Microwave Background (CMB) Data – Gives lower values (~67-70 km/sec/Mpc).

2. Local Distance Ladder (Cepheids, Supernovae, etc.) – Gives higher values (~73-77 km/sec/Mpc).

3. Other Probes (Gravitational Waves, Strong Lensing, etc.) – Intermediate values (~200-260 km/sec/Mpc in some alternative studies).

Role of Dark Energy

Dark energy is the driving force behind the accelerated expansion of the universe. In the early universe, gravity from matter dominated, slowing expansion. But as the universe expanded, the density of matter decreased, allowing dark energy’s repulsive effect to take over. This led to:

Acceleration of expansion (not just constant speed).

Increasing Hubble parameter over time in some models (explaining why different epochs may show different expansion rates).

Possible variations in H₀ measurements due to how different probes perceive expansion at different distances (early vs. late universe).

Conclusion

The variation in H₀ values may reflect real physical changes due to dark energy's evolving influence, or systematic issues in measurement techniques. If the Hubble constant truly changes over cosmic time, it could suggest that dark energy itself evolves rather than remaining constant, challenging the standard ΛCDM model.

Article Which Theory Truly Unifies?

Although I had already taken my leave, a few private conversations made it clear to me that I could no, in good conscience, disappear without leaving this behind. Not as an answer, but as a question sharpened to its essence.

For those still wondering what true unification logically requires, I’ve formulated this framework: one generator, no auxiliary postulates. It’s a challenge, not a conclusion. The rest is up to each reader.