Thursday, November 02, 2017

Dark nucleosynthesis and stellar evolution

The temperature of the solar core is rather near to the scale of dark nuclear binding energy. This co-incidence inspires interesting questions about the dark nucleosynthesis in the stellar evolution.

1. Some questions inspired by a numerical co-incidence

The temperature at solar core is about T=1.5× 107 K corresponding to the thermal energy E= 3T/2= 2.25 keV obtained by a scaling factor 2-11 energy ∼ 5 MeV, which is the binding energy scale for the ordinary nuclei. That this temperature corresponds to the binding energy scale of dark nuclei might not be an accident.

That the temperature in the stellar core is of the same order of magnitude as dark nuclear binding energy is a highly intriguing finding and encourages to ask whether dark nuclear fusion could be the key step in the production of ordinary nuclei and what is the relation of dark nucleosynthesis to ordinary nucleosynthesis.

  1. Could dark nucleosynthesis occur also pre-stellar evolution and thus proceed differently from the usual p-p-cycle involving fusion processes? The resulting ordinary nuclei would undergo only ordinary nuclear reactions and decouple from the dark dynamics. This does not exclude the possibility that the resulting ordinary nuclei form nuclei of nuclei with dark protons: this seems to occur also in nuclear transmutations.

  2. There would be two competing effects. The higher the temperature, the less stable dark nuclei and the longer the dark nuclear strings. At lower temperatures dark nuclei are more stable but transform to ordinary nuclei decoupling from the dark dynamics. The liberated nuclear binding energy however raises the temperature and makes dark nuclei less stable so that the production of ordinary nuclei in this manner would slow down.

    At what stage ordinary nuclear reactions begin to dominate over dark nucleosynthesis? The conservative and plausible looking view is that p-p cycle is indeed at work in stellar cores and has replaced dark nucleosynthesis when dark nuclei became thermally unstable.

    The standard view is that solar temperature makes possible tunnelling through Coulomb wall and thus ordinary nuclear reactions. The temperature is few keVs and surprisingly small as compared to the height of Coulomb wall Ec∼ Z1Z2e2/L, L the size of the nucleus. There are good reasons to believe that this picture is correct. The co-incidence of the two temperatures would make possible the transition from dark nucleosynthesis to ordinary nucleosynthesis.

  3. What about dark nuclear reactions? Could they occur as reconnections of long magnetic flux tubes? For ordinary nuclei reconnections of short flux tubes would take place (recall the view about nuclei as two-sheeted structures). For ordinary nuclear the reactions at energies so low that the phase transition to dark phase (somewhat analogous to the de-confinement phase transition in QCD) is not energetically possible, the reactions would occur in nuclear scale.

  4. An interesting question is whether dark nucleosynthesis could provide a new manner to achieve ordinary nuclear fusion in laboratory. The system would heat itself to the temperatures required by ordinary nuclear fusion as it would do also during the pre-stellar evolution and when nuclear reactor is formed spontaneously (Oklo reactor).

2. Could dark nucleosynthesis affect the views about stellar evolution?

The presence of dark nucleosynthesis could modify the views about star formation, in particular about energy production in protostars and pre-main-sequence stars (PMS) following protostars in stellar evolution.

In protostars and PMSs the temperature is not yet high enough for the burning of hydrogen to 4He, and according to the standard model the energy radiated by the star consists of the gravitational energy liberated during the gravitational contraction. Could dark nucleosynthesis provide a new mechanism of energy production and could this energy be transferred from the protostar/PMS as dark energy along dark magnetic flux tubes?

Can one imagine any empirical evidence for the presence of dark nucleosynthesis in protostars and PMSs?

  1. The energy and matter produced in dark nucleosynthesis could partially leak out along dark magnetic flux tubes and give rise to astrophysical jets. Astrophysical jets indeed accompany protostars and the associated planetary and bipolar nebulae as well as PMSs (T Tauri stars and Herbig-Haro objects). The jets along flux tubes associated with hot spots at which dark nucleosynthesis would take place could provide also a mechanism for the transfer of angular momentum from the protostar/PMS.

  2. Spectroscopic observations of dense cores (protostar) not yet containing stars indicate that contraction occurs but the predicted expansion of the contracting region has not been observed (see this). The energy production by dark nucleosynthesis could increase pressure and slow down and even prevent the expansion of the contracting region.

How dark nucleosynthesis could affect the evolution of protostars and PMSs?
  1. In standard model the formation of accretion disk could be understood in terms of angular momentum conservation: spherical distribution of matter transforms to a planar one does not require large changes for the velocities tangential to the plane. The mechanism for how the matter from accretion disk spirals into star is however poorly understood.

  2. The TGD inspired model for galaxy formation suggests that the core region of the protostar is associated with a highly knotted cosmic string ("pearl in a necklace") forming the dark core of galaxy with constant density of dark matter (see this). The dark matter from the cosmic string would have leaked out from the cosmic string and transformed to ordinary matter already before the annihilation of quarks and antiquarks. The CP, P, and T asymmetries predicted by twistor lift of TGD would predict that there is a net quark (antiquark) number outside (inside) the cosmic string. The locally axisymmetric gravitational potential of the cosmic string would favour disk like rather than spherically symmetric matter distribution as the initial distribution of the baryonic matter formed in the hadronization from the quarks left from the annihilation.

    Quantitative model is needed to see whether dark fusion could contribute significantly to the energy production in protostars and PMSs and affect their evolution. The nuclear binding energy liberated in dark fusion would slow down the gravitational contraction and increase the duration of protostar and PMS phases. In standard model PMS phase is possible for masses varying from 2 to 8 solar masses. Dark nucleosynthesis could increase the upper bound for the mass of PMS from that predicted by the standard model.

See the article Cold fusion again or the chapter of "Hyper-finite factors, p-adic length scale hypothesis, and dark matter hierarchy" with the same title. See also the article Cold fusion, low energy nuclear reactions, or dark nuclear synthesis?.

For a summary of earlier postings see Latest progress in TGD.

Articles and other material related to TGD.

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