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J. Krol

Publications and source records attributed to J. Krol.

12 recordsLinked to original sources

A topological approach to Neutrino masses by using exotic smoothness

In this paper, we will consider a cosmological model with two topological transitions of the space. The smooth 4-dimensional spacetime of the model admits topological transitions of its 3-dimensional slices. The whole approach is inspired by a class of exotic smoothness structure on $S^{3}\times\mathbb{R}$. In particular, this class of smoothness structures induces two topological transitions. Then, we are able to calculate the energy scales as associated to these topological transitions. For the first transition we will get the value of the GUT scale and the energy of the second transition is at the electroweak scale. The topology of the exotic $S^{3}\times\mathbb{R}$ determines both, the energy of the scales by certain topological invariants, and the existence of the right-handed sterile neutrino. It is the input for the seesaw mechanism. Secondly, based on this model, we are able to calculate the neutrino masses which are in a very good agreement with experiments. Finally, we will speculate, again based on topology, why there are three generations of neutrinos and an asymmetry between neutrinos and anti-neutrinos.

hep-th

How to obtain a cosmological constant from small exotic R^4

In this paper we determine the cosmological constant as a topological invariant by applying certain techniques from low dimensional differential topology. We work with a small exotic $R^{4}$ which is embedded into the standard $\mathbb{R}^{4}$. Any exotic $R^4$ is a Riemannian smooth manifold with necessary non-vanishing curvature tensor. To determine the invariant part of such curvature we deal with a canonical construction of $R^4$ where it appears as a part of the complex surface $K3\#\overline{CP(2)}$. Such $R^{4}$'s admit hyperbolic geometry. This fact simplifies significantly the calculations and enforces the rigidity of the expressions. In particular, we explain the smallness of the cosmological constant with a value consisting of a combination of (natural) topological invariant. Finally, the cosmological constant appears to be a topologically supported quantity.

gr-qc

Inflation and topological phase transition driven by exotic smoothness

In this paper we will discuss a model which describes the cause of inflation by a topological transition. The guiding principle is the choice of an exotic smoothness structure for the space-time. Here we consider a space-time with topology $S^{3}\times\mathbb{R}$. In case of an exotic $S^{3}\times\mathbb{R}$, there is a change in the spatial topology from a 3-sphere to a homology 3-sphere which can carry a hyperbolic structure. From the physical point of view, we will discuss the path integral for the Einstein-Hilbert action with respect to a decomposition of the space-time. The inclusion of the boundary terms produces fermionic contributions to the partition function. The expectation value of an area (with respect to some surface) shows an exponential increase, i.e. we obtain inflationary behavior. We will calculate the amount of this increase to be a topological invariant. Then we will describe this transition by an effective model, the Starobinski or $R^{2}$ model which is consistent with the current measurement of the Planck satellite. The spectral index and other observables are also calculated. Finally we obtain a realistic cosmological constant.

gr-qc

Decoherence in quantum cosmology and the cosmological constant

We discuss a spacetime having the topology of $S^{3}\times\mathbb{R}$ but with a different smoothness structure. The initial state of the cosmos in our model is identified with a wildly embedded 3-sphere (or a fractal space). In previous work we showed that a wild embedding is obtained by a quantization of a usual (or tame) embedding. Then a wild embedding can be identified with a (geometrical) quantum state. During a decoherence process this wild 3-sphere is changed to a homology 3-sphere. We are able to calculate the decoherence time for this process. After the formation of the homology 3-sphere, we obtain a spacetime with an accelerated expansion enforced by a cosmological constant. The calculation of this cosmological constant gives a qualitative agreement with the current measured value.

gr-qc

On the origin of inflation by using exotic smoothness

In this paper we discuss a spacetime having the topology of S^3 x R but with a different smoothness structure leading to a geometric model for inflation, called geometric inflation. In particular this spacetime is not globally hyperbolic and we obtain a time line with a spatial topology change from the 3-sphere to a homology 3-sphere and back. The topology of the spacetime remains invariant. Among the infinite possible smoothness structures of this spacetime, we choose a homology 3-sphere constructed from the knot 8_{10} with hyperbolic geometry, i.e. admitting a homogenous metric of negative scalar curvature. We discuss the accelerated expansion for FLRW cosmology caused by the topology change. In contrast to other inflation models, this process stops after a finite time. Alternatively, the topology change can be also described by a SU(2)-valued scalar field. Then we calculate the expansion rate (having more than 60 e-folds) and the energy time scale. The coupling to matter is also interpreted geometrically and the reheating process (as well the supercooled expansion during inflation) is naturally obtained. The model depends only on a single parameter, a topological invariant of the homology 3-sphere, and assumes a Planck size universe of S^3-topology. The dependence of the model on the initial state and the a geometric interpretation of quantum fluctuations are also discussed.

gr-qc

Quantum Geometry and Wild embeddings as quantum states

In this paper we discuss wild embeddings like Alexanders horned ball and relate them to fractal spaces. We build a $C^{\star}$-algebra corresponding to a wild embedding. We argue that a wild embedding is the result of a quantization process applied to a tame embedding. Therefore quantum states are directly the wild embeddings. Then we give an example of a wild embedding in the 4-dimensional spacetime. We discuss the consequences for cosmology.

gr-qc

On topological restrictions of the spacetime in cosmology

In this paper we discuss the restrictions of the spacetime for the standard model of cosmology by using results of the differential topology of 3- and 4-manifolds. The smoothness of the cosmic evolution is the strongest restriction. The Poincare model (dodecaeder model), the Picard horn and the 3-torus are ruled out by the restrictions but a sum of two Poincare spheres is allowed.

gr-qc

Exotic Smoothness and Quantum Gravity II: exotic R^4, singularities and cosmology

Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. In the second paper, we calculate the "smoothness structure" part of the path integral in quantum gravity for the exotic R^4 as non-compact manifold. We discuss the influence of the "sum over geometries" to the "sum over smoothness structure". There are two types of exotic R^4: large (no smooth embedded 3-sphere) and small (smooth embedded 3-sphere). A large exotic R^4 can be produced by using topologically slice but smoothly non-slice knots whereas a small exotic R^4 is constructed by a 5-dimensional h-cobordism between compact 4-manifolds. The results are applied to the calculation of expectation values, i.e. we discuss the two observables, volume and Wilson loop. Then the appearance of naked singularities is analyzed. By using Mostow rigidity, we obtain a justification of area and volume quantization again. Finally exotic smoothness of the R^4 produces in all cases (small or large) a cosmological constant.

gr-qc

On 4-dimensional Lorentz-structures, Dark energy and Exotic smoothness

Usually, the topology of a 4-manifolds $M$ is restricted to admit a global hyperbolic structure $Σ\times\mathbb{R}$. The result was obtained by using two conditions: existence of a Lorentz structure and causality (no time-like closed curves). In this paper we study the influence of the smoothness structure to show its independence of the two conditions. Then we obtain the possibility for a topology-change of the 3-manifold $Σ$ keeping fix its homology. We will study the example $S^{3}\times\mathbb{R}$ with an exotic differential structure more carefully to show some implications for cosmology. Especially we obtain an interpretation of the transition in topology as dark energy.

gr-qc

Pure 4-geometry of quantum magnetic spin matter from Kondo effect

We determine a smooth Euclidean 4-geometry on R^4 from quantum interacting spin matter like in the multichannel Kondo effect. The CFT description of both: the $k$-channel Kondo effect of spin magnetic impurities quantum interacting with spins of conducting electrons and exotic smooth R^4, by the level $k$ WZW model on SU(2), indicates the relation between smooth R^4's and the quantum matter. We propose a model which shows: exotic smooth R^4_k generates fermionic fields via the topological structure of Casson handles and when this handle is attached to some subspace A of R^4 these fermions represent electrons bounded by the magnetic impurity. Thus the Kondo bound state of $k$ conducting electrons with magnetic impurity of spin $s$ is created like in the low temperature Kondo effect. Then the quantum character of the interactions is encoded in 4-exoticness. The complexity as well the number of Casson handles correspond to the number of channels in the Kondo effect. When the smoothness structure is the standard one, no quantum interactions are carried on by standard R^4.

hep-th

Topological quantum D-branes and wild embeddings from exotic smooth R^4

This is the next step of uncovering the relation between string theory and exotic smooth R^4. Exotic smoothness of R^4 is correlated with D6 brane charges in IIA string theory. We construct wild embeddings of spheres and relate them to a class of topological quantum Dp-branes as well to KK theory. These branes emerge when there are non-trivial NS-NS H-fluxes where the topological classes are determined by wild embeddings S^2 -> S^3. Then wild embeddings of higher dimensional $p$-complexes into S^n correspond to Dp-branes. These wild embeddings as constructed by using gropes are basic objects to understand exotic smoothness as well Casson handles. Next we build C*-algebras corresponding to the embeddings. Finally we consider topological quantum D-branes as those which emerge from wild embeddings in question. We construct an action for these quantum D-branes and show that the classical limit agrees with the Born-Infeld action such that flat branes = usual embeddings.

hep-th

Exotic smooth R^4 and certain configurations of NS and D branes in string theory

In this paper we show that in some important cases 4-dimensional data can be extracted from superstring theory such that a) the data are 4 Euclidean geometries embedded in standard $\mathbb{R}^{4}$, b) these data depend on NS and D brane charges of some string backgrounds, c) it is of potential relevance to 4-dimensional physics, d) the compactification and stabilization techniques are not in use, but rather are replaced. We analyze certain configurations of NS and D-branes in the context of $SU(2)$ WZW model and find the correlations with different exotic smoothings of $\mathbb{R}^{4}$. First, the dynamics of D-branes in $SU(2)$ WZW model at finite $k$, i.e. the charges of the branes, refers to the exoticness of ambient $\mathbb{R}^{4}$. Next, the correspondence between exotic smoothness on 4-space, transversal to the world volume of NS5 branes in IIA type, and the number of these NS5 branes follows. Finally, the translation of 10 dimensional string backgrounds to 4 Euclidean spaces embedded as open subsets in the standard $\mathbb{R}^{4}$ is achieved.

hep-th