arXiv subjects

Maria Titova

Publications and source records attributed to Maria Titova.

6 recordsLinked to original sources

arXiv2026

Optical probing of Wigner crystallization in monolayer WSe$_2$ via diffraction of longitudinal excitons

Monolayer transition metal dichalcogenides (TMDs) are characterized by relatively large carrier effective masses and suppressed screening of the Coulomb interaction, which substantially enhances the correlation effects in these structures. The direct band gap allows to effectively optically probe these correlations. Here, we present an experimental observation of Wigner crystallization in monolayer $\mathrm{WSe}_2$ probed by the measurement of the exciton diffraction on the Wigner crystal (WC) periodic potential. We observe the formation of the WC phase in the absence of external magnetic fields at temperature range $T<26~\mathrm{K}$ and carrier concentrations $n$ $<2\times10^{11}~\mathrm{cm}^{-2}$. The direct observation of the exciton diffraction is enabled by the strong exciton longitudinal-transverse splitting induced by the long-range intervalley exchange interaction, leading to the large detuning between main exciton peak and first diffraction peak. Our findings highlight that the valley degree of freedom of charge carriers in TMDs facilitates optical probing of correlated electron phases in these structures.

cond-mat.mes-hall↗

arXiv2025

Persuasion with Verifiable Information

This paper studies a game in which an informed sender with state-independent preferences uses verifiable messages to convince a receiver to choose an action from a finite set. We characterize the equilibrium outcomes of the game and compare them with commitment outcomes in information design. We provide conditions under which a commitment outcome is an equilibrium outcome and identify environments in which the sender does not benefit from commitment power. Our findings offer insights into the interchangeability of verifiability and commitment in applied settings.

econ.TH↗

arXiv2025

Targeted Advertising in Elections

How does targeted advertising influence electoral outcomes? This paper presents a one-dimensional spatial model of voting in which a privately informed challenger persuades voters to support him over the status quo. I show that targeted advertising enables the challenger to persuade voters with opposing preferences and swing elections decided by such voters; under simple majority, the challenger can defeat the status quo even when it is located at the median voter's bliss point. Ex-ante commitment power is unnecessary -- the challenger succeeds by strategically revealing different pieces of verifiable information to different voters. Publicizing all political ads would mitigate the negative effects of targeted advertising and help voters collectively make the right choice.

econ.TH↗

arXiv2025

Revealed and Concealed Repression: Theory and Measurement

Regimes routinely conceal acts of repression. We show that observed repression may be negatively correlated with total repression, consisting of both revealed and concealed acts. This distortion can generate perverse effects for policy interventions designed to reduce repression and complicates inference about the causes and consequences of repression. We develop a model in which regimes choose whether to conceal repression and activists decide whether to challenge the regime. We identify two measurement problems - one due to concealment and one to deterrence. We construct indices of repression that account for these problems and show how these indices can be expressed in terms of observable variables by leveraging equilibrium relationships. We then propose an empirical strategy to estimate these indices. As a proof of concept, we apply this approach to Russia, estimating repression indices at a monthly frequency for 2020-2025.

econ.TH↗

arXiv2022

Withholding Verifiable Information

We study a class of finite-action disclosure games in which the sender's preferences are state-independent and the receiver's optimal action depends only on the expected state. While receiver-preferred equilibria in these games involve full revelation, other equilibria are less well understood. We show that any equilibrium payoff can be obtained with a disclosure strategy corresponding to a partition with a laminar structure that allows pooling of nonadjacent states. In a sender-preferred equilibrium, such a structure balances inducing more sender-favorable actions with deterring deviations. Leveraging this insight, we identify conditions under which the sender does not benefit from commitment power. We then apply these results to study selling with quality disclosure and influencing voters.

econ.TH↗

arXiv2013

New bounds for the distance Ramsey number

In this paper we study the distance Ramsey number $R_{{\it D}}(s,t,d)$. The \textit{distance Ramsey number} $R_{{\it D}}(s,t,d) $ is the minimum number $n$ such that for any graph $ G $ on $ n $ vertices, either $G$ contains an induced $ s $-vertex subgraph isomorphic to a distance graph in $ \Real^d $ or $ \bar {G} $ contains an induced $ t $-vertex subgraph isomorphic to the distance graph in $ \Real^d $. We obtain the upper and lower bounds on $R_{{\it D}}(s,s,d),$ which are similar to the bounds for the classical Ramsey number $R(\lceil \frac{s}{[d/2]} \rceil, \lceil \frac{s}{[d/2]} \rceil)$.

math.CO↗