arXiv subjects

Otar Sepper

Publications and source records attributed to Otar Sepper.

5 recordsLinked to original sources

arXiv2026

Slippage-at-Risk (SaR): A Forward-Looking Liquidity Risk Framework for Perpetual Futures Exchanges

We introduce $\textbf{Slippage-at-Risk (SaR)}$, a quantitative framework for measuring liquidity risk in perpetual futures exchanges. Unlike backward-looking metrics such as Value-at-Risk computed on historical returns or realized deficit distributions, SaR provides a \emph{forward-looking} assessment of liquidation execution risk derived from current order book microstructure. The framework comprises three complementary metrics: $SaR(\alpha)$, the cross-sectional slippage quantile; $ESaR(\alpha)$, the expected slippage in the distributional tail; and $TSaR(\alpha)$, the aggregate dollar-denominated tail slippage. We extend the base framework with a \emph{concentration adjustment} that penalizes fragile liquidity structures where a small number of market makers dominate quote provision. Drawing on recent work by Chitra et al. (2025) on autodeleveraging mechanisms and insurance fund optimization, we establish a direct mapping from SaR metrics to optimal capital requirements. Empirical analysis using Hyperliquid order book data, including the October 10, 2025 liquidation cascade, demonstrates SaR's predictive validity as a leading indicator of systemic stress. We conclude with practical implementation guidance and discuss philosophical implications for risk management in decentralized financial systems.

q-fin.RM↗

arXiv2014

Possible restoration of superconductivity in the quasi-one-dimensional conductor Li$_{0.9}$Mo$_6$O$_{17}$ in feasibly high pulsed magnetic fields, $H \simeq 100 \ T$

We present a theoretical study of restoration of superconductivity in the form of the triplet reentrant superconducting phase in a quasi-one-dimensional (Q1D) conductor. Substitution of known band and superconducting parameters of the presumably triplet Q1D superconductor Li$_{0.9}$Mo$_6$O$_{17}$ into our theoretical equations shows that such restoration can happen in feasibly high non-destructive pulsed magnetic field of the order of $H \simeq 100 \ T$. We investigate in detail how small inclinations of a direction of a magnetic field from its best experimental geometry decrease superconducting transition temperature of the reentrant phase, which is important for its possible experimental discovery.

cond-mat.supr-con↗

arXiv2014

Quantum Limit in a Magnetic Field for Triplet Superconductivity in a Quasi-One-Dimensional Conductor

We theoretically consider the upper critical magnetic field, perpendicular to a conducting axis in a triplet quasi-one-dimensional superconductor. In particular, we demonstrate that, at high magnetic fields, the orbital effects against superconductivity in a magnetic field are reversible and, therefore, superconductivity can restore. It is important that the above mentioned quantum limit can be achieved in presumably triplet quasi-one-dimensional superconductor Li$_{0.9}$Mo$_6$O$_{17}$ [J.-F. Mercure et al., Phys. Rev. Lett. {\bf 108}, 187003 (2012)] at laboratory available pulsed magnetic fields of the order of $H = 500-700 \ T$.

cond-mat.supr-con↗

arXiv2013

Nodeless Versus Nodal Scenarios of Possible Triplet Superconductivity in the Quasi-One-Dimensional Layered Conductor Li$_{0.9}$Mo$_6$O$_{17}$

We consider the problem of the orbital upper critical magnetic field, parallel to the most conducting axis of a quasi-one-dimensional layered superconductor. It is shown that superconductivity can be destroyed through orbital effects at fields much higher than the so-called Clogston-Chandrasekhar paramagnetic limiting field, $H_p$, provided that superconducting pairing of electrons are of a triplet nature. We demonstrate that the superconducting state of the quasi-one-dimensional layered conductor, $\mathrm{Li_{0.9}Mo_6O_{17}}$, is well described by the suggested theory. To this end, we consider two competing scenarios: 1: a superconducting order parameter without zeros on the Fermi surface, and 2: one with zeros on the Fermi surface - both are shown to lead to destruction of superconductivity at a magnetic field, $H^x_{c_2}$, five times higher than $H_p$. With recent experimental measurements on the $\mathrm{Li_{0.9}Mo_6O_{17}}$ favoring the nodeless order parameter, we present a strong argument supporting triplet pairing in this compound.

cond-mat.supr-con↗

arXiv2012

Phenomenological Approach to the Possible Existence of a Triplet Superconducting Phase in the Quasi-One-Dimensional Conductor Li$_{0.9}$Mo${_6}$O$_{17}$

We consider a theoretical problem of the upper critical magnetic field parallel to a conducting axis of a quasi-one-dimensional layered superconductor. We show that the orbital effects against superconductivity in a magnetic field are capable of destroying the superconducting phase at low temperatures if the interplane distance is less than the corresponding coherence length. Applications of our results to the recent experiments, performed in the superconductor Li$_{0.9}$Mo$_6$O$_{17}$ [J.-F. Mercure et al., Phys. Rev. Lett. {\bf 108}, 187003 (2012)], provide strong arguments in favor of a triplet superconducting pairing in this quasi-one-dimensional layered conductor.

cond-mat.supr-con↗