Hydrodynamics of the Dark Superfluid: I. Genesis of Fundamental Particles Marco Fedi
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Hydrodynamics of the dark superfluid: I. genesis of fundamental particles Marco Fedi To cite this version: Marco Fedi. Hydrodynamics of the dark superfluid: I. genesis of fundamental particles. 2017. hal- 01549082v2 HAL Id: hal-01549082 https://hal.archives-ouvertes.fr/hal-01549082v2 Preprint submitted on 19 Jul 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. manuscript No. (will be inserted by the editor) Hydrodynamics of the dark superfluid: I. genesis of fundamental particles. Marco Fedi Received: date / Accepted: date Abstract Here we consider the existence of an ubiquitous 1 Introduction: a superfluid universe? dark superfluid which fills the universe corresponding to dark energy (∼ 70% of the universe mass-energy, also expressed K.Huang has dedicated a book [11] to the possibility that in the cosmological constant) and dark matter. As in oth- our universe possess superfluid features. Here we want to er superfluids, quantum vortices would originate, whose ge- continue the theoretical investigation, also taking into ac- ometry can describe the spin of fundamental particles, sug- count recent experiments and observations and in this first gesting the validity of a quantum hydrodynamic approach paper concerning the hydrodynamics of the dark superflu- to particle physics. This seething dark superfluid would also id we focus on fundamental particles described as topolog- justify the continuous formation and annihilation of virtu- ical defects (quantum vortices) in this dark medium. Data al particles and antiparticles in quantum vacuum as vortex- from the ESA Planck Space Observatory say that dark ener- antivortex pairs, letting us reinterpret quantum vacuum as gy constitutes 69:1% of the universe mass-energy. The only hydrodynamic spontaneous fluctuations of this dark super- detectable effect currently attributed to dark energy is its re- fluid. In this case, it would be correct to say that dark en- pulsive force, which opposes gravity and causes a supposed ergy (or rather the dark superfluid) does not interact with (we propose a different, superfluid cosmological model [2]) our baryon world unless it is hydrodynamically perturbed, accelerated expansion of the universe. Since it is otherwise in which case it could even correspond to the particles of the undetectable and its density does not affect the motion of Standard Model. Antimatter and its absence in the universe, the celestial bodies, it is believed that it does not interac- as well as particle decay may also have place in a superflu- t with ordinary matter. On the contrary, we speculate that id model, completing the picture, while fundamental forces it may be a fundamental superfluid, whose internal pres- exerted by particles, such as gravity or electromagnetism, sure opposes gravity [2,7] –– indeed the energy of vacu- have their hydrodynamic equivalents in the Bernoulli force um per unit volume, whose value1 is currently believed to which may cause attraction or repulsion between quantum be ∼ 6 · 10−9J=m3 from WMAP measurements, has units of vortices. As regards the repulsive force attributed to dark pressure –– and whose hydrodynamic perturbation may even energy in cosmology, it would depend on the internal pres- correspond to the known massive fundamental particles, as sure of the dark superfluid, represented by its energy density, quantized vortices, a picture thanks to which we can also while the cosmic microwave background at ∼ 2:72K would understand quantum vacuum and the infinite pairs of virtual be its superfluidity temperature, consistent with those of oth- particles and antiparticles which continuously form and an- er superfluids as 4He. nihilate in it, probably as vortex-antivortex pairs, as indeed observed in other superfluids and in polariton condensates Keywords superfluid vacuum · dark energy · dark matter · [42,43], also at room temperature [19]. Quantum vacuum or particle physics · spin here the cosmic and ubiquitous dark superfluid2 (DS), would PACS 95.36.+x · 03.75.Kk · 03.65.-w · 03.75.Nt · 95.35.+d 1 resorting to the upper value of the cosmological constant, other- M. Fedi wise a much higher value according to quantum electrodynamics. See Ministero dell’Istruzione, dell’Universita` e della Ricerca (MIUR), also [2] Sect. 2 for the problem of vacuum energy density. Rome, Italy 2 we believe that here the term dark energy may be confusing as it E-mail: [email protected]; [email protected] does not underline its mass density and hypothesized superfluidity. The 2 Marco Fedi be a cosmic Bose-Einstein condensate (BEC) [1,7,4–6,8– 12] of dark energy’s quanta, we call them dark superfluid quanta (DSQ). An analogy with the granular, quantized s- pacetime of Loop Quantum Gravity [13,14] shall be report- ed, in which the superfluidity of the spin network should not be excluded. The existence of a false vacuum with non-zero energy content is definitively accepted and proven in a lot of physical phenomena as the Lamb shift, the Casimir effect, the Unruh effect, the anomalous magnetic moment, vacuum birefringence [35] etc. All these phenomena could be root- ed in the ubiquitous DS. Its quantum granular, foamy nature seems to have been confirmed by G. Amelino-Camelia in a recent statistical analysis on the observation of neutrinos and photons using to data from the IceCube and the Fermi GLAST [44]. Let us reflect on vacuum fluctuations 4E4t ≥ h¯: (1) H The circulation in a quantized vortex, C v · dl= nh=m, mul- tiplied by mass becomes the Bohr-Sommerfeld quantization Fig. 1 Left: (a) Metal atoms trapped in superfluid helium vortices high- light a structure of vortex filaments [31]; (b) galactic filaments of dark condition, expressing mass circulation in a quantized vortex matter which baryon matter aggregates on forming stars and galax- I ies [45]. Here the relationship between dark energy and dark matter is p · dx = nh: (2) the same existing between superfluid helium and the vortex filaments C which manifest in it, i.e. we suppose dark matter is a hydrodynamic For n = 1, Eq. (2) tells us that the quantum of action, h; ac- manifestation of dark energy [5,12]. tually refers to a complete turn along a circular path, per- formed by a quantum whose momentum is p. In (1) 2p profiles of orbital velocities are believed to be due to, we (h¯ = h=2p) also refers to a complete turn and we can inter- arrive at ∼ 95%. Thus, we are probably facing a superfluid pret vacuum fluctuations as the circulation of DSQ in quan- universe [11,12]. tized vortices during a time 4t (1), before vortex-antivortex The temperature of the cosmic microwaves background annihilation occurs. radiation (CMB), ∼ 2:72 K, would be in reasonable agree- Quantum vortices are known to manifest in superfluids, ment with the temperature of other superfluids such as 4He. 4 as in superfluid He [10,15], so this interpretation of quan- Fig. 1 shows dark matter distribution in the universe in anal- tum fluctuations is a first clue to think of quantum vacuum ogy with the structure of a vortex web arising in a familiar as a superfluid. Furthermore, fermions spin-½ may be de- superfluid (4He). Within this analogy all the space among scribed in hydrodynamic terms as the circulation of DSQ the filaments is occupied by liquid helium in (a) and by the in a torus vortex (see Sect. 3). Thus, if vacuum fluctuations DS in (b). Moreover in (a) the filaments are made visible are superfluid vortices, where is the underlying superfluid in using metallic atoms which adhere to the vortices, while which they arise? in (b) baryon matter (dust, gases) adhere to the vortices of Also according to Huang [11], the possible answers are dark matter making them visible in a similar way. Indeed we either the Higgs field or dark energy, both observed as “dark” do not directly observe dark matter but its “pilot-action”on scalar fields. Being the Higgs boson the fundamental exci- baryon matter’s dynamics. tation of the Higgs field, it is probably a vortex itself, so The equation of state of cosmology for a single-fluid we opt for dark energy, as a cosmic fundamental scalar field model can be referred to superfluid dark energy, where Pd with superfluid features. After all, we know it constitutes and rd are respectively pressure and density of dark energy ∼ 69% of the mass-energy of the universe, also expressed [37] in the cosmological constant, L = kr0, of Einstein field e- 00 Pd quation, where r0 (T ; as regards the stress-energy tensor) w = (3) indicates the density of dark energy. Along with dark matter, rd which can be interpreted as a quantum hydrodynamic man- Treating the universe as a fluid medium is therefore already ifestation of dark energy itself [5,12] and whose existence a standard praxis in cosmology. The analogy showed in Fig. is evident in the dark halos of spiral galaxies which the flat 1 let us also suppose that the universe was (or still is) spin- definition dark superfluid also helps to understand dark matter as a hy- ning (we confirm that in the superfluid cosmological model drodynamic manifestation of superfluid vacuum, as we argue (Fig.1). [2]). But to be precise, it would be the DS filling the uni- Hydrodynamics of the dark superfluid: I. genesis of fundamental particles.