arXiv subjects

L. Clavelli

Publications and source records attributed to L. Clavelli.

At least 19 recordsLinked to original sources

arXiv2019

Extending the susy model to core-collapse supernovae

A notable feature of the two standard models for thermonuclear and core-collapse supernovae is that, although these two models are fundamentally different, the respective supernova types have quite similar rates and appearances. For instance, both types occur one to several times per century per typical galaxy and both types seed the universe with the heavy elements essential to life. In spite of this, neither standard model provides a reasonably problem-free description of its target phenomenon. A major obstacle to providing a unified picture of supernovae would seem to be the fact that type Ia supernovae occur typically with gigayear delay times after the cessation of carbon fusion while the core-collapse explosions occur only days after such fusion cessation. In this article we study the possibility of extending the successful supersymmetric model for type Ia supernovae to core-collapse events. The question is whether and under what assumptions a phase transition to an exact supersymmetric background can efficiently explain both type Ia and core collapse supernovae.

astro-ph.HE↗

arXiv2018

Host Galaxy Effects in the Susy Model for Supernovae Ia

For more than forty years virtually all work on the theory of type Ia Supernovae (SN Ia) has assumed that these explosions were due to the transfer of mass to a degenerate star from a partner in a binary system. In these binary models, when the mass of one partner closely approaches the Chandrasekhar maximum for a stable degenerate system, fusion can be initiated and the star explodes. However, there are now a number of indications that fusion could instead be triggered by a phase transition in a sub-Chandrasekhar white dwarf star. Although these indications provide no clue as to what specific phase transition initiates the explosion, it is possible that remarkable and well established host galaxy effects as considered in the present work could point to a specific source of the energy deposition. These host galaxy correlations are, at first glance, surprising since the typical distance scale of white dwarf stars is the earth radius while the typical distance between stars is at the light year scale. Performing a least $χ^2$ fit to the delay time distribution to fix parameters, we give predictions from the susy phase transition model for the host galaxy effects. In addition we discuss a susy insight into the Phillips relation which is basic to the cosmological importance of the type Ia supernovae.

astro-ph.HE↗

arXiv2017

Six indications of radical new physics in supernovae Ia

After more than forty years since the basic standard model for supernovae Ia was proposed many astronomers are still hopeful that this phenomenon will ultimately be understood in terms of Newtonian gravity plus nuclear and particle physics as they existed in the 1930's. In spite of this fact there are at least six nagging puzzles in supernova physics that suggest some radical new physics input may be necessary. "Radical" in this context means a physics idea that did not exist in the 1930's and that is still not experimentally confirmed in 2017.

astro-ph.HE↗

arXiv2016

Degeneracy breakdown as a source of supernovae Ia

We pursue the investigation of a model for sub-Chandrasekhar supernovae Ia explosions (SNIa) in which the energy stored in the Pauli tower is released to trigger a nuclear deflagration. The simplest physical model for such a degeneracy breakdown is a phase transition to an exactly supersymmetric state in which the scalar partners of protons, neutrons, and leptons become degenerate with the familiar fermions of our world as in the supersymmetric standard model with susy breaking parameters relaxed to zero. We focus on the ability of the susy phase transition model to fit the total SNIa rate as well as the delay time distribution of SNIa after the birth of a progenitor white dwarf. We also study the ejected mass distribution and its correlation with delay time. Finally, we discuss the expected SNIa remnant in the form of a black hole of Jupiter mass or lower and the prospects for detecting such remnants.

astro-ph.HE↗

arXiv2016

Finite Matter Resolution of the Cosmological Entropy Problem

We discuss how entropy bounds, which are not respected in the standard cosmology, constrain the parameters of a previously suggested cosmology with a finite total mass. In that alternative cosmology the matter density was postulated to be a spatial delta function at the time of the big bang thereafter diffusing rapidly outward with constant total mass. Also discussed here are some related issues including the cosmic onion question, the information content of the universe, and the question of whether light trapping regions exist on a cosmic scale.

gr-qc↗

arXiv2015

Einstein's Equations and a Cosmology with Finite Matter

We discuss various space-time metrics which are compatible with Einstein's equations and a previously suggested cosmology with a finite total mass. In this alternative cosmology the matter density was postulated to be a spatial delta function at the time of the big bang thereafter diffusing outward with constant total mass. This proposal explores a departure from standard assumptions that the big bang occurred everywhere at once or was just one of an infinite number of previous and later transitions.

gr-qc↗

arXiv2012

An Alternative String Landscape Cosmology: Eliminating Bizarreness

In what has become a standard eternal inflation picture of the string landscape there are many problematic consequences and a difficulty defining probabilities for the occurrence of each type of universe. One feature in particular that might be philosophically disconcerting is the infinite cloning of each individual and each civilization in infinite numbers of separated regions of the multiverse. Even if this is not ruled out due to causal separation one should ask whether the infinite cloning is a universal prediction of string landscape models or whether there are scenarios in which it is avoided. If a viable alternative cosmology can be constructed one might search for predictions that might allow one to discriminate experimentally between the models. We present one such scenario although, in doing so, we are forced to give up several popular presuppositions including the absence of a preferred frame and the homogeneity of matter in the universe. The model also has several ancillary advantages. We also consider the future lifetime of the current universe before becoming a light trapping region.

astro-ph.CO↗

arXiv2011

String Landscape and Supernovae Ia

We present a model for the triggering of Supernovae Ia (SN Ia) by a phase transition to exact supersymmetry (susy) in the core of a white dwarf star. The model, which accomodates the data on SN Ia and avoids the problems of the standard astrophysical accretion based picture, is based on string landscape ideas and assumes that the decay of the false broken susy vacuum is enhanced at high density. In a slowly expanding susy bubble, the conversion of pairs of fermions to pairs of degenerate scalars releases a significant amount of energy which induces fusion in the surrounding normal matter shell. After cooling, the absence of degeneracy pressure causes the susy bubble to collapse to a black hole of about 0.1 solar mass or to some other stable susy object.

hep-ph↗

arXiv2011

A supersymmetric model for triggering Supernova Ia in isolated white dwarfs

We propose a model for supernovae Ia explosions based on a phase transition to a supersymmetric state which becomes the active trigger for the deflagration starting the explosion in an isolated sub-Chandrasekhar white dwarf star. With two free parameters we fit the rate and several properties of type Ia supernovae and address the gap in the supermassive black hole mass distribution. One parameter is a critical density fit to about $3 \cdot 10^7$ g/cc while the other has the units of a space time volume and is found to be of order $0.05\,$ Gyr $R_E^3$ where $R_E$ is the earth radius. The model involves a phase transition to an exact supersymmetry in a small core of a dense star.

astro-ph.HE↗

arXiv2010

Nuclear Physics in a Susy Universe

We refine a previous zeroth order analysis of the nuclear properties of a supersymmetric (susy) universe with standard model particle content plus degenerate susy partners. No assumptions are made concerning the Higgs structure except we assume that the degenerate fermion/sfermion masses are non-zero. This alternate universe has been dubbed Susyria and it has been proposed that such a world may exist with zero vacuum energy in the string landscape.

hep-ph↗

arXiv2009

Probing Metastability at the LHC

Current attempts to understand supersymmetry (susy) breaking are focused on the idea that we are not in the ground state of the universe but, instead, in a metastable state that will ultimately decay to an exactly susy ground state. It is interesting to ask how experiments at the Large Hadron Collider (LHC) will shed light on the properties of this future supersymmetric universe. In particular we ask how we can determine whether this final state has the possibility of supporting atoms and molecules in a susy background.

hep-ph↗

arXiv2008

Covalent Molecular Binding in a Susy Background

The Pauli Exclusion principle plays an essential role in the structure of the current universe. However, in an exactly supersymmetric (susy) universe, the degeneracy of bosons and fermions plus the ability of fermions to convert in pairs to bosons implies that the effects of the Pauli principle would be largely absent. Such a universe may eventually occur through vacuum decay from our current positive vacuum energy universe to the zero vacuum energy universe of exact susy. It has been shown that in such a susy universe ionic molecular binding does exist but homonuclear diatomic molecules are left unbound. In this paper we provide a first look at covalent binding in a susy background and compare the properties of the homonuclear bound states with those of the corresponding molecules in our universe. We find that covalent binding of diatomic molecules is very strong in an exact susy universe and the interatomic distances are in general much smaller than in the broken susy universe.

hep-th↗

arXiv2008

Metastable Aspects of Singlet Extended Higgs Models

It has long been known that the broken supersymmetric (susy) phase of the singlet extended susy higgs model (SESHM) is at best metastable and the ground states of the model have vanishing vacuum energy and are exactly supersymmetric. If the SESHM is confirmed at the Large Hadron Collider (LHC), the numerical values of the parameters of the model have a bearing on key properties of the susy phase and might provide an estimate of the remaining time before a possible decay of our false vacuum. We provide some analysis of the model including a treatment of phases in the potential and soft higgs masses.

hep-ph↗

arXiv2008

Landscape Implications of Extended Higgs Models

From several points of view it is strongly suggested that the current universe is unstable and will ultimately decay to one that is exactly supersymmetric (susy). The possibility that atoms and molecules form in this future universe requires that the degenerate electron/selectron mass is non-zero and hence that electroweak symmetry breaking (EWSB) survives the phase transition to exact susy. However, the minimal supersymmetric standard model (MSSM) and several of its extensions have no EWSB in the susy limit. Among the extended higgs models that have been discussed one stands out in this regard. The higgs sector that is revealed at the Large Hadron Collider (LHC) will therefore have implications for the future universe. We also address the question as to whether the transition to the exact susy phase with EWSB is exothermic.

hep-ph↗

arXiv2007

Extended Higgs Models and a Transition to Exact Susy

String landscape ideas and the observation of a positive vacuum energy in the current universe suggest that there could be a future transition to an exactly supersymmetric world. Atomic and molecular binding in this susy background probably require that electroweak symmetry breaking survives the transition. Among several susy higgs models that have been discussed, one stands out in this regard. Thus, the higgs structure that is revealed at the LHC could have strong consequences for the type of bulk matter that may arise in a future susy universe.

hep-ph↗

arXiv2007

Ionic Binding in a Susy Background

From string theory and the observation of a positive vacuum energy in our universe it seems inevitable that there will eventually be a phase transition to an exactly supersymmetric (susy) universe. In this phase there will be an effective weakening of the Pauli principle due to fermi-bose degeneracy. As a consequence molecular binding will be significantly affected. We make some general comments on susy molecules and perform a variational principle estimate of ionic binding energies.

hep-ph↗

arXiv2007

Phase Transition to Exact Susy

The anthropic principle is based on the observation that, within narrow bounds, the laws of physics are such as to have allowed the evolution of life. The string theoretic approach to understanding this observation is based on the expectation that the effective potential has an enormous number of local minima with different particle masses and perhaps totally different fundamental couplings and space time topology. The vast majority of these alternative universes are totally inhospitable to life, having, for example, vacuum energies near the natural (Planck) scale. The statistics, however, are assumed to be such that a few of these local minima (and not more) have a low enough vacuum energy and suitable other properties to support life. In the inflationary era, the "multiverse" made successive transitions between the available minima until arriving at our current state of low vacuum energy. String theory, however, also suggests that the absolute minimum of the effective potential is exactly supersymmetric. Questions then arise as to why the inflationary era did not end by a transition to one of these, when will the universe make the phase transition to the exactly supersymmetric ground state, and what will be the properties of this final state.

hep-ph↗

arXiv2006

Problems in a weakless universe

The fact that life has evolved in our universe constrains the laws of physics. The anthropic principle proposes that these constraints are sometimes very tight and can be used to explain in a sense the corresponding laws. Recently a "disproof" of the anthropic principle has been proposed in the form of a universe without weak interactions, but with other parameters suitably tuned to nevertheless allow life to develop. If a universe with such different physics from ours can generate life, the anthropic principle is undermined. We point out, however, that on closer examination the proposed "weakless" universe strongly inhibits the development of life in several different ways. One of the most critical barriers is that a weakless universe is unlikely to produce enough oxygen to support life. Since oxygen is an essential element in both water, the universal solvent needed for life, and in each of the four bases forming the DNA code for known living beings, we strongly question the hypothesis that a universe without weak interactions could generate life.

hep-ph↗