Nicolò Piccione

Piccione, Nicolo

Gravitational Poissonian Spontaneous Localization Model of Hybrid Quantum-Classical Newtonian Gravity: Energy Increase and Experimental Bounds Journal Article

In: Class. Quantum Grav., 2026, ISSN: 1361-6382.

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Piccione, Nicolò

Diffusion minimization via optimal smearing in collapse and hybrid classical-quantum gravitational models Journal Article

In: Phys. Rev. A, vol. 113, no. 6, 2026, ISSN: 2469-9934.

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@article{Piccione2026,

title = {Diffusion minimization via optimal smearing in collapse and hybrid classical-quantum gravitational models},

author = {Nicolò Piccione},

doi = {10.1103/h74z-zvfv},

issn = {2469-9934},

year  = {2026},

date = {2026-06-09},

journal = {Phys. Rev. A},

volume = {113},

number = {6},

publisher = {American Physical Society (APS)},

abstract = {<jats:p>

                    Spontaneous diffusion (i.e., nonconservation of energy) is a prominent, testable prediction of collapse and hybrid classical-quantum gravitational models. Without smearing of the mass density operator, the associated heating (or energy increase) rate diverges, yet the smearing distribution is arbitrary and, on scales much larger than the smearing length

                    <a:math xmlns:a="http://www.w3.org/1998/Math/MathML">

                      <a:msub>

                        <a:mi>r</a:mi>

                        <a:mi>C</a:mi>

                      </a:msub>

                    </a:math>

                    , much of the phenomenology is expected to be insensitive to this choice. We propose to resolve this arbitrariness as follows: for a fixed

                    <b:math xmlns:b="http://www.w3.org/1998/Math/MathML">

                      <b:msub>

                        <b:mi>r</b:mi>

                        <b:mi>C</b:mi>

                      </b:msub>

                    </b:math>

                    , select the distribution that minimizes the heating rate. Conceptually, this should identify the minimal deviation from standard quantum mechanics and provide models that, once experimentally refuted, would strongly disfavor all variants with different distributions. We apply this approach to the most investigated collapse models: GRW (for Ghirardi-Rimini-Weber), CSL (for continuous spontaneous localization), and DP (for Diósi-Penrose). Notably, the Gaussian is optimal only for the GRW case. Finally, we apply it to the Tilloy-Diósi hybrid classical-quantum model of Newtonian gravity, leading to its minimally deviating variant. This version of the model is entirely determined by only one free parameter

                    <c:math xmlns:c="http://www.w3.org/1998/Math/MathML">

                      <c:msub>

                        <c:mi>r</c:mi>

                        <c:mi>C</c:mi>

                      </c:msub>

                    </c:math>

                    , and, if experimentally refuted, would strongly disfavor any other version of it.

                  </jats:p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

Close

Spontaneous diffusion (i.e., nonconservation of energy) is a prominent, testable prediction of collapse and hybrid classical-quantum gravitational models. Without smearing of the mass density operator, the associated heating (or energy increase) rate diverges, yet the smearing distribution is arbitrary and, on scales much larger than the smearing length
<a:math xmlns:a="http://www.w3.org/1998/Math/MathML">
<a:msub>
<a:mi>r</a:mi>
<a:mi>C</a:mi>
</a:msub>
</a:math>
, much of the phenomenology is expected to be insensitive to this choice. We propose to resolve this arbitrariness as follows: for a fixed
<b:math xmlns:b="http://www.w3.org/1998/Math/MathML">
<b:msub>
<b:mi>r</b:mi>
<b:mi>C</b:mi>
</b:msub>
</b:math>
, select the distribution that minimizes the heating rate. Conceptually, this should identify the minimal deviation from standard quantum mechanics and provide models that, once experimentally refuted, would strongly disfavor all variants with different distributions. We apply this approach to the most investigated collapse models: GRW (for Ghirardi-Rimini-Weber), CSL (for continuous spontaneous localization), and DP (for Diósi-Penrose). Notably, the Gaussian is optimal only for the GRW case. Finally, we apply it to the Tilloy-Diósi hybrid classical-quantum model of Newtonian gravity, leading to its minimally deviating variant. This version of the model is entirely determined by only one free parameter
<c:math xmlns:c="http://www.w3.org/1998/Math/MathML">
<c:msub>
<c:mi>r</c:mi>
<c:mi>C</c:mi>
</c:msub>
</c:math>
, and, if experimentally refuted, would strongly disfavor any other version of it.

Close

Piccione, Nicolò; Bassi, Angelo

Hybrid classical-quantum Newtonian gravity with stable vacuum Journal Article

In: Class. Quantum Grav., vol. 42, no. 22, 2025, ISSN: 1361-6382.

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