Is it "natural" to expect Economics to become a part of the Natural Sciences?

We are in the middle of a complex debate as to whether Economics is really a proper natural science. The 'Discussion & Debate' issue of this Euro. Phys. J. Special Topic volume is: 'Can economics be a Physical Science?' I discuss some aspects here.Comment: 7 pages; EPJ-ST special issue on 'Can Economics be a Physical Science?' Edited by S. Sinha, A. S. Chakrabarti & M. Mitr

Flavours and Infra-red Instability in Holography

Within a phenomenological holographic model in $(4+1)$-bulk dimensions, defined by Einstein-gravity with a negative cosmological constant, coupled to a Dirac-Born-Infeld and a Chern-Simons term, we explore the fate of BF-bound violation for a probe scalar field and a fluctuation mode of the corresponding geometry. We assume this simple model to capture the dynamics of a strongly coupled SU$(N_c)$ gauge theory with $N_f$ fundamental matter, which in the limit ${\cal O} \left( N_c \right) \sim {\cal O}\left(N_f\right)$ and with a non-vanishing matter density, is holographically described by an AdS$_2$-geometry in the IR. We demonstrate that, superconductor/superfluid instabilities are facilitated and spontaneous breaking of translational invariance is inhibited with increasing values of $\left(N_f / N_c \right)$. This is similar, in spirit, with known results in large $N_c$ Quantum Chromodynamics with $N_f$ quarks and a non-vanishing density, in which the chiral density wave phase becomes suppressed and superconducting instabilities become favoured as the number of quarks is increased.Comment: 24 pages, 2 figure

Effective Temperature in Steady-state Dynamics from Holography

We argue that, within the realm of gauge-gravity duality, for a large class of systems in a steady-state there exists an effective thermodynamic description. This description comes equipped with an effective temperature and a free energy, but no well-defined notion of entropy. Such systems are described by probe degrees of freedom propagating in a much larger background, e.g. $N_f$ number of ${\cal N} =2$ hypermultiplets in ${\cal N}=4$ $SU(N_c)$ super Yang-Mills theory, in the limit $N_f \ll N_c$. The steady-state is induced by exciting an external electric field that couples to the hypermultiplets and drives a constant current. With various stringy examples, we demonstrate that an open string equivalence principle determines a unique effective temperature for all fluctuations in the probe-sector. We further discuss various properties of the corresponding open string metric that determines the effective geometry which the probe degrees of freedom are coupled to. We also comment on the non-Abelian generalization, where the effective temperature depends on the corresponding sector of the fluctuation modes.Comment: 48 pages, 2 figure