Related papers: The fermionic double smeared null energy condition
We present a consistent effective theory that violates the null energy condition (NEC) without developing any instabilities or other pathological features. The model is the ghost condensate with the global shift symmetry softly broken by a…
The Averaged Null Energy Condition (ANEC) states that the integral along a complete null geodesic of the projection of the stress-energy tensor onto the tangent vector to the geodesic cannot be negative. ANEC can be used to rule out…
In the free three-dimensional space, we consider a pair of identical $\uparrow$ fermions of some species or in some internal state, and a pair of identical $\downarrow$ fermions of another species or in another state. There is a resonant…
Dynamical dark energy (DE) phenomenon emerges as a geometrical effect accompanying the cosmological expansion of nonrelativistic fermionic matter. This occurs without the need for any fluid, like e.g. dynamical scalar field (quintessence,…
The emergence of free fermionic string models with solely the MSSM charged spectrum below the string scale provides further evidence to the assertion that the true string vacuum is connected to the Z_2 x Z_2 orbifold in the vicinity of the…
Consequences of a non-trivial scalar field background for an effective 4D theory were studied in the context of one compact extra dimension. The periodic background that appears within the (1+4)-dimensional $\phi^4$ theory was found and the…
We present the complete family of higher dimensional spacetimes that admit a geodesic, shearfree, twistfree and expanding null congruence, thus extending the well-known D=4 class of Robinson-Trautman solutions. Einstein's equations are…
We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory (DCSGT). The universe we live in is taken as the real part of the whole spacetime ${\cal M}^4_C(J)$ which is double complex.…
The unfolded formulation for arbitrary massless mixed-symmetry bosonic and fermionic fields in Minkowski space is constructed. The unfolded form is proved to be uniquely determined by the requirement that all gauge symmetries are manifest.…
A free fermion without doubler is formulated on 1+D dimensional discrete Minkowski space-time. The action is not hermitian but causes no harm. In 1+3 dimensional massless case the equation describes a single species of Dirac particle in the…
In this work, we have studied an "exponential form" of spacetime metric: \begin{equation*} ds^2 = -e^{-\frac{2m}{r}}dt^2 +e^{\frac{2m}{r}}dr^2 + e^{\frac{2m}{r}}[r^2 d\theta^2 + r^2 \sin^2\theta d\phi^2] \end{equation*} in some of the…
Quantum critical phenomena may be qualitatively different when massless Dirac fermions are present at criticality. Using our recently-discovered fermion-sign-free Majorana quantum Monte Carlo (MQMC) method introduced by us in Ref. [1], we…
Boundary conditions for a massless Dirac fermion in 2+1 dimensions where the space is a half-plane are discussed in detail. It is argued that linear boundary conditions that leave the Hamiltonian Hermitian generically break $C$ $P$ and $T$…
We test the theoretical free energy surface (FES) for two-step nucleation (TSN) proposed by Iwamatsu [J. Chem. Phys. 134, 164508 (2011)] by comparing the predictions of the theory to numerical results for the FES recently reported from…
We study a lattice model of interacting Dirac fermions in $(2+1)$ dimension space-time with an SU(4) symmetry. While increasing interaction strength, this model undergoes a {\it continuous} quantum phase transition from the weakly…
Solutions to the equations of motion of the low energy, effective field theory emerging out of compactified heterotic string theory are constructed by making use of the well-known duality symmetries. Beginning with four-dimensional…
We give a simplified approach to Kunzinger & Saemann's theory of Lorentzian length spaces in the globally hyperbolic case; these provide a nonsmooth framework for general relativity. We close a gap in the regularly localizable setting, by…
The asymptotically flat structure of $\mathcal{N}=(2,0)$ supergravity in three spacetime dimensions is explored. The asymptotic symmetries are spanned by an extension of the super-BMS$_3$ algebra, with two independent $\hat{u}(1)$ currents…
Fermionic atoms in a large-scale, homogeneous optical lattice provide an ideal quantum simulator for investigating the fermionic Hubbard model, yet achieving this remains challenging. Here, by developing a hybrid potential that integrates a…
Quantum fields can notoriously violate the null energy condition (NEC). In a cosmological context, NEC violation can lead to, e.g., dark energy at late times with an equation-of-state parameter smaller than $-1$ and nonsingular bounces at…